THE BOTANIC GARDENer: Winter 2024 - Issue 62 by BGANZ

The magazine for botanic garden professionals

Theme: Fighting the extinction battle – the crucial role of botanic gardens in threatened species conservation

ISSN 1446-2044 | www.bganz.org.au

Editorial Committee

REBECCA HARCOURT

Managing Editor

DALE ARVIDSSON

Curator, Brisbane Botanic Gardens and High Profile Parks

ALAN MATCHETT

Botanic Garden Manager, Dunedin Botanic Garden

TOM McCARTER

Head of NHM Gardens, The Natural History Museum, London

JANET O’HEHIR

Secretary, Camperdown Botanic Gardens and Arboretum Trust Inc.

CASSANDRA NICHOLS

Chief Executive Officer, BGANZ

SIOBHAN DUFFY

Graphic Designer

DISCLAIMER: Please note the views expressed in articles are not necessarily the views of BGANZ Ltd. We aim to encourage a broad range of articles.

Feedback and comments on the newsletter and articles are welcome. Please email: secretariat@bganz.org.au

ACKNOWLEDGEMENT OF COUNTRY:

BGANZ acknowledges the traditional owners of Country throughout Australia, and their continuing connection to land, sea and community. We pay our respects to them and their cultures, and to Elders past, present and emerging.

COVER: Royal Tasmanian Botanical Gardens staff assessing a seed orchard of the threatened species, Eastcoast Paperdaisy Xerochrysum bicolor.

Credit: James Wood RTBG

2 Editorial insights

Rebecca Harcourt, Managing Editor

Feature interview

4 Nathan Emery: fighting the extinction battle seed‑by‑seed

Feature

Garden

13 Saving threatened species at the Australian Botanic Garden Mount Annan – one ecological community at a time

Dr Peter Cuneo, Honorary Research Associate, Australian PlantBank, Australian Botanic Garden Mount Annan and David Khoury, Supervisor Natural Areas & Open Spaces, Australian Botanic Garden Mount Annan

Feature

Articles

18 From the nursery to the field: horticulture informs translocation of Small Purple Pea Swainsona recta

Zoe Knapp, Peter Bredell, Emma Cook (ACT Government), Bek Hyland and Tom North, Australian National Botanic Gardens

23 Joining forces: aligning ex situ and in situ threatened plant conservation programs to support regional priorities

Emma Simpkins, Senior Regional Advisor Flora at Auckland Council and Ella Rawcliffe, Botanical Records and Conservation Specialist at Auckland Botanic Gardens

Pollinating Great Ideas

27 Perennial management and garden design

Meg Awatea Spittal, Horticultural Apprentice, Auckland Botanic Gardens, Aotearoa New Zealand

30 Hidden assets

Lorraine Perrins, former staff member and current volunteer, Royal Tasmanian Botanical Gardens

Notes From the Nursery

33 The role of botanic gardens in fighting the extinction battle

Matthew Nicholson, volunteer editor, Notes from the Nursery

Specialist Groups

38 News from BCARM, the BGANZ Collection and Record Management group

Sheree Parker, BCARM Chair and Supervisor, Geelong Botanic Gardens

40 We speak for the trees. The role of arborists in botanic gardens and the value of our trees

Ian Allan, Chair BARB and Supervisor Natural Areas & Arboriculture, Blue Mountains Botanic Garden, Mount Tomah

What’s new?

43 Botanic news: from home and abroad

Cassandra Nichols, CEO, BGANZ Ltd

The theme of the next edition of The BOTANIC GARDENer is Botanic gardens – people and plants for a sustainable future. The deadline for contributions is 14 October 2024

Please contact the Managing Editor (managing.editor@bganz.org.au) if you are intending to submit an article or have a contribution to other sections.

Editorial insights

Rebecca Harcourt, Managing Editor

Welcome to Issue 62 of THE BOTANIC GARDENer. I’d like to acknowledge that I live and work in Copacabana, NSW, on the land of the Garigal Clan of the Wannanginni Guringai people, who are the ancestral custodians of Bulbararing, Allagai and Tdjudibaring, and pay my respects to their Elders past, present and emerging.

While researching this issue’s theme, Fighting the extinction battle – the crucial role of botanic gardens in threatened species conservation, I came across a report from the Royal Botanic Gardens Kew containing some sobering statistics1 – 45% of known flowering plant species are at risk of extinction. It’s also thought that 77% of the estimated 100,000 species of vascular plants still be described are likely to be threatened. Botanic gardens are surely the best places to combat these threats.

The 3,000+ botanic gardens worldwide contain 41% of plants classified as threatened2 . Many of these gardens have the facilities, skills and expertise to tackle the extinction crisis. This issue contains articles from three such gardens, the Australian Botanic Garden Mount Annan, the Australian National Botanic Gardens and Auckland Botanic Gardens. These articles also highlight the value of botanic gardens working collaboratively to protect threatened species, not just with other gardens, but with local, state and federal governments, traditional owners, networking organisations, and others.

After reading this issue, I think botanic gardens are the not‑so‑secret weapons in the fight against plant extinction.

Rebecca

P.S. I’d be very interested to hear any feedback on this issue or suggestions for future themes. Please feel free to email me at managing.editor@bganz.org.au.

1 Royal Botanic Gardens Kew. State of the world’s plants and fungi 2023 https://doi.org/10.34885/wnwn 6s63

2 Westwood, M, Cavender, N, Meyer, A, et al. (2021). Botanic garden solutions to the plant extinction crisis. Plants People Planet, 3(1):22–32. https://nph.onlinelibrary.wiley.com/doi/full/10.1002/ppp3.10134

Rebecca Harcourt

Grow as a Leader in Public Horticulture

The Fellows Program develops tomorrow’s leaders, preparing them to successfully navigate pressing challenges, develop thoughtful strategies, and lead organizations that are equitable and sustainable.

During the fully funded, cohort-based residency, Fellows engage in project-based learning that allows them to hone their professional skills while delving into issues relevant to the horticulture industry today.

Applications open June 1, 2024 and close July 31, 2024 for the 2025–2026 cohort. Learn more and apply at longwoodgardens.org/ fellows-program.

Pictured above:

The 2023–2024 Fellows Cohort, from left to right: Nathan Anderson, Muluken Nega Kebede, Abigail Lorenz, Colin Skelly, Edem Kojo Doe.

Nathan Emery: fighting the extinction battle seed-by-seed

Rebecca Harcourt interviews Nathan Emery

, Manager of the Seedbank & Conservation Collections in the Australian PlantBank, based at the Australian Botanic Garden Mount Annan.

Nathan’s interest in plants started during his many childhood cicada hunting adventures in the bush with his father. While he still hunts cicadas in his spare time, his day job revolves around the seedbank, and includes both lab work and fieldwork. I chatted to Nathan about his work as a seed scientist and ecologist, which involves seed collection and research, plant monitoring, threatened species translocation and restoration.

How did you become interested in seeds?

My fascination with seeds started when I came across a book called Australian Seeds (Sweedman & Merritt, 2006). I must have been 20 or 21, between second and third year university. I read that cover to cover and became fascinated with seeds and then the notion of seed banking and seed conservation.

You work at the Australian PlantBank. What is it?

PlantBank is a $20 million state of the art germplasm research and conservation facility. At its heart is the ex situ conservation seedbank that holds over 13,000 seed collections representing about 20–25% of Australia’s flora. We have about 5,000 Australian species in the seedbank, with around half of New South Wales’ endemic seedbearing flora and 72% of New South Wales’ threatened flora.

Alongside the seedbank are germination and research facilities. Scientists like me use these and the collection to undertake seed biological research to better understand how we can store, maintain and grow our native flora. There’s also the tissue culture collection and cryostorage facilities for what we call ‘exceptional’ or recalcitrant species. These are the species whose seeds don’t tolerate

Nathan Emery

orthodox conditions to slow their ageing, which we do by drying the seeds to a small percentage of their moisture content before placing them in storage at −20 °C. Usually these seeds have a lot of internal oils and lipids that tend to break down at −20 °C, destroying their viability. There are also species like many of the Myrtle Rust affected plants that just aren’t producing viable seeds. Putting them into tissue culture or growing them from cuttings and incorporating them into the living collection is the main way we can conserve these species in the absence of seed material.

What’s the process once the seeds are brought into the PlantBank?

We remove all the non‑seed material collected with the seeds and check seed quality. This involves looking at the fill rate1 of seeds because plants produce different proportions of empty seeds, or the seeds may have been damaged by predators. We want to limit the amount of non‑viable material in the collection where possible. We then do a viability test. The best way to determine the viability of a collection is by germinating the seeds. We then dry the collection down under controlled environmental conditions at 15 °C and 15% relative humidity to about 5% of its original moisture content. This limits the moisture in the seeds and the amount of ice crystals that can form when frozen2

Caley’s Grevillea Grevillea caleyi, found only around the northern Sydney suburbs of Belrose, Duffys Forest/Terrey Hills and Ingleside, is listed as Critically Endangered and is part of the NSW Government’s Saving our Species program. Credit: Nathan Emery

Cross section of a Grevillea caleyi seed showing the white viable endosperm, indicating that the seeds are ready for collecting. Credit: Nathan Emery

1 A measure of the proportion of visually undamaged seeds that have all the tissues essential for germination, i.e. an intact endosperm and embryo. This is usually performed by X‑ray or a cut test.

2 The formation of ice crystals in living cells may lead to the bursting of the cell or an increase in the concentration of minerals to a toxic level. Both are usually fatal.

We then store the seeds at −20 °C, which slows the ageing rate of the seeds considerably. For some species viability can be maintained in storage for years, others, decades, or for some of our harder seeded species like the acacias, it can be up to 100 years.

Although the ageing process is significantly delayed, it still occurs, with seeds losing viability over time, albeit more slowly. This means that as well as understanding their initial viability when they go into storage, we must continue to monitor the viability to see how they’re progressing over time. We need to know whether they’ve dropped below a viability level that would trigger a re collection or a propagation event to get more seed material if that population or that species doesn’t exist in the wild at that time or at some time in the future.

Seed banking is the most cost-effective way of maintaining collections ex situ.

We will store collections or seek collections of species even if they have 10 or 50 seeds, because that’s still critical genetic material. Where we can’t collect seeds, we have to look at other collection methods. This is typically through vegetative cutting or propagation and that’s where our horticulturalists in the nursery get involved. These plants may also get incorporated into the tissue culture or cryostorage collection. They may also be incorporated into the living collection across our three botanic garden sites.

Which species do you focus on?

A key focus for us is on the species listed in the New South Wales Biodiversity Conservation (BC) Act 2016. We work with New South Wales Department of Climate Change, Energy, Environment and Water to prioritise species within that list based on several considerations, such as their listing status. It makes sense to target those that are Critically Endangered and Endangered because they’re obviously on the fast path to decline and extinction.

We also focus on species for which we don’t have representative collections in the seed bank or in the living collection here at the gardens, as well as species that have complex seed dormancy and seed germination requirements. It’s one thing to make collections of threatened species and put them in the bank but if we don’t understand how to propagate them and grow them into plants, what’s the point of holding them in a repository?

Do you treat the threatened species differently to other species?

We’re starting to treat them a little bit differently in how we prioritise the collecting strategy: what we collect and how we collect it out in the field. Threatened species tend to have lower genetic diversity. This is inherent in many of these species because they’re in small populations, often very isolated and fragmented, and this is part of the reason why they are threatened in the first

place. Often there’s a short term or even an immediate need to translocate these species, or build resilience into declining populations by adding new genetic diversity to them.

We are now employing a strategy where we collect seeds of threatened species by maternal line, keeping the seed collected from maternal plants separate (van der Merwe et al., 2023). Traditionally, we would bulk all the collections in what we term a composite collection, but now we are looking to retain the genetic integrity of these collections. This is so that when genetic data on these species become available, we can relate it back to our collections and look at those genotypes and understand where the diversity lies within those maternal lines. We can also better identify if we have, by accident, picked clones or hybrids. If we have a composite collection, it is difficult to separate and identify the diversity within it. In cases where specific genetic diversity is needed, these collections have a greater risk of failing to meet that requirement. That’s really the main difference that we’re employing between threatened species and common species at the moment. We are using this strategy as a test case to see whether it’s a viable strategy for all species. We can always bulk the seeds later for whatever purpose. Once they are bulked in the field, however, you can never really tease them apart.

The Wee Jasper Grevillea Grevillea iaspicula is found only in southern NSW in the Wee Jasper area and on the shores of Lake Burrinjuck, with about 100 plants in existence. It is listed as Critically Endangered and is part of the Saving our Species program.

Credit: Nathan Emery

We have a genetics team within the Botanic Gardens of Sydney (BGoS), the Research Centre for Ecological Resilience (RCER), that checks the genetics. They have refined and published workflows for genomics sequencing and studies on plant species in which they address several key conservation and taxonomic questions (Rossetto et al., 2021). This relies on the collection of leaf material from plants that are the target species, but in a lot of cases there may be additional sampling from closely related taxa; for example, if there’s an issue with taxonomic integrity of those species, such as if you’ve got a lot of subspecies or perhaps a species that’s split by one or two morphological characteristics.

We collect leaf samples of the maternal plants as well as seeds. We then have the linked genetic data to those seed maternal lines. The beautiful thing about sampling leaf material is once it’s freeze dried, it can stay in storage for (almost!) eternity. This means we can collect material for which there might not be funding for genetic sampling immediately, but it’s still there for when funding becomes available. That helps our collection strategy and planning in two ways. First, if the genetic studies have been performed, we can better target our collecting strategy for specific populations or genotypes where we know the diversity is present. Secondly, we can employ best practice to sample leaf material geographically representatively across populations. Then, when funding becomes available, we have that data linked so we can go back and look at our collections and see how well we guesstimated the genetic diversity. Did we capture it sufficiently or are there additional populations or pockets of diversity that we need to go back and supplement our collections with?

The beautiful thing about sampling leaf material is once it’s freeze-dried, it can stay in storage for (almost!) eternity.

How close are you to holding insurance populations for your current threatened species list?

We have just over 72% of plants classified as under threat by the New South Wales BC Act 2016 secured by at least one seed collection in the seedbank, but that doesn’t include any additional species that may be represented in our living collections.

If species are stored by at least one collection, it doesn’t necessarily mean that they’re representatively sampled or secured, but there is at least some level of genetic security as an insurance for those species. We’d really like to be able to confidently say that we have 72% of all those species representatively sampled across their known genetic diversity and distribution. It’s a new way of thinking about collections, rather than just going out and making collections systematically. We want to know, for example, how to propagate them, how to germinate them and what relaxes their seed dormancy, so we have all the information and as much material available as possible.

Are you looking to prevent other plants from joining the threatened species list or are you focusing only on the current ones on the list?

Our seedbanking program is statewide. It includes all New South Wales species, and we have an ongoing collection program. A lot of our external funding and external projects are threatened species related because that’s where a lot of the focus is but Threatened Ecological Communities (TEC) are also starting to receive more funding, which is great to see. The focus over the last probably 10 to 15 years has, however, been on threatened species as the major target for us (for example, see Cuneo et al., 2018).

Collecting seed of Mountain Burr‑Daisy Calotis cuneata from the understorey of remnant Brigalow woodland. This was part of a NSW Environmental Trust and Saving our Species grant project that focused on the ex situ conservation of TECs in northwest NSW, which included Brigalow TEC3 Credit: Nathan Emery

What is the value of all botanic gardens working collaboratively on threatened species?

I think botanic gardens are stewards of conservation. The best place to conserve any species is in its natural habitat, but where that’s just not possible, that’s where botanic gardens play a vital role, not just ensuring against extinction, but also understanding more about the ecological requirements of those plants – what they need to be able to survive and to reproduce so that they persist in the environment, and indeed into changing environments in the future.

Through collaborations we can ensure a broader collection of genetic material that is secured across multiple sites, helping to mitigate the risk of losing plant diversity. It also supports the exchange of research findings, data and best practices for managing ex situ collections of threatened species. Joint initiatives among botanic gardens can lead to stronger outreach and education programs, raising public awareness about the importance of conserving threatened species.

What do you need facility-wise to be part of threatened species protection?

It varies on a species by species basis. There are species with orthodox seeds that can be stored using typical conditions. We have a walk in freezer that’s set to −20 °C, but you can store seeds when they’re dried down in the fridge or you can put them into a standard home freezer to preserve their viability over time.

Where it becomes more difficult is where we have these ‘exceptional’ species that don’t really conform to standard international procedures. We recently published a collaborative paper that discusses the various types of exceptional species and the knowledge gaps associated with them (Martyn Yenson et al., 2024). That’s where it becomes difficult for organisations with fewer resources to be able to conserve those species due to these knowledge gaps. This is where major botanic gardens like the BGoS can focus because we have the appropriate facilities and capacity.

3 Brigalow Acacia harpophylla (either dominant in the tree layer or co‑dominant with other species) is a TEC found in NSW and QLD. Nationally, Brigalow has declined to about 10% of its former area.

Nathan Emery sorting through seed collections in the Cool Room Seedbank vault (4 °C) at the Australian PlantBank. Credit: BGoS

It’s critical that we share this information with other organisations so that they can better understand whether they have the capacity or the facilities to be able to also include that particular species as part of their day to day operations or, for example, whether they need to seek more funding to get further facilities.

What advice would you have for some of those smaller regional gardens if they wanted to get involved in conserving their local flora?

Being part of collaborative networks and groups like BGANZ is great to get information on what’s out there and to engage with other botanic gardens. From BGoS’s perspective, too, we’d love to know what regional botanic gardens have in their living collections and what capacity they have for additional species as well.

In our Wollemi Pine work, we’ve developed the idea of metacollections. These are small groups of plants that represent a significant percentage of a species’ diversity. We’ve propagated a ‘metacollection pack’ for the Wollemi Pine that we sent out to different botanic gardens across the world to lower the risk of genetic loss in this species. There are certainly other candidates for such metacollections where it would be of significant benefit, for example, the Myrtle Rust affected species. I think projects like this really help to showcase or increase the value of regional botanic gardens, demonstrating that they’re stewards of species that are in decline.

What is one of the highlights you’ve experienced working with threatened species?

The most recent one was what we called securing a ‘holy grail’ type species (Emery, 2024). It’s an Endangered aquatic plant called Aponogeton queenslandicus and is only known in New South Wales from a single, temporary swamp habitat northwest of Bourke. We’ve attempted to go out there and collect it multiple times when the conditions seem right, but we just haven’t been able to find it. We were told in March this year that there were hundreds of plants flowering and starting to produce seed. That was an exciting piece of news, so we dropped everything and organised a whirlwind trip out to Bourke. We secured seeds and exhumed some plants to bring back to place in water tanks in the nursery with the hope of being able to collect further seed. We also wanted to potentially incorporate these into the living collection here at the BGoS.

This collecting trip was critical because the site is in a temporary water body. By the time the team got out there, a lot of it was just mud and a lot of the plants were starting to die back to their tuberous roots. It was really a massive win for us — being able to secure this species and start to understand more about its germination and dormancy requirements. Then we can relate this information back to conditions on the ground and get a better understanding of whether the intensity or the duration of the boom–bust environment with droughts and floods might impact the species’ persistence in that environment into the future.

I’m happy to say that the exhumed plants in the water tanks survived and grew. Now that it’s cooler they’ve died back and hopefully will persist via tubers. We will maintain them through to spring and summer to see whether they reshoot under warmer temperatures, but in the meantime, we’re processing the seed and germination testing the seed collections.

We collected seeds using maternal line sampling and leaf samples for genetic testing. The capacity of our collecting program to do this type of work all over the state is important, as some parts

Seedbank Officer Ruby Paroissien collecting Aponogeton queenslandicus seeds from an ephemeral swamp, west of Bourke, NSW, as part of the Saving our Species program (left); wading through an ephemeral swamp in search of Aponogeton queenslandicus (right). Credit: Stefanie Carusi

of New South Wales may not see another human for a long time. It’s important that when we’re there, we’re not just thinking about collecting the seed of our target species. We think about whether there is value in collecting leaf samples or in collecting as much environmental information about that area as possible because it may be useful for that species or another species’ ongoing conservation management. We really try to take the time to be able to collect as much material and as much information as we can.

What is your favourite part of the job?

I don’t know whether there is a favourite! I enjoy the whole process of being able to understand what we have in the collection, identify where the gaps are and then work towards plugging those gaps. Making those collections out in the field is really satisfying — to put seed into a bag is always exhilarating. But it’s just as exhilarating to bring that collection back, put it into the germination incubators and understand its temperature and moisture requirements, or find out if it requires post fire triggers. Does it need smoke water or heat shock to relax dormancy and enable that seed or that species to germinate? It’s also fantastic to be able to communicate the findings with others, whether it’s in a scientific paper, a conference presentation, a presentation to the public — or in this magazine!

Further

reading

Cuneo, P, Emery, N, Errington, G et al. (2018). Assisted run(a)way: translocation planning to secure the Bankstown Hibbertia. Australasian Plant Conservation, 27(1):23–25. http://dx.doi.org/10.5962/p.373747

Emery, N (2024). The holy grail: scientists collect seeds from rare aquatic plant. Botanic Gardens of Sydney website. https://www.botanicgardens.org.au/discover and learn/watch listen read/holy grail scientists collect seeds rare aquatic plant#

Martyn Yenson, A, Sommerville, K, Guja, L et al. (2024). Ex situ germplasm collections of exceptional species are a vital part of the conservation of Australia’s national plant treasures. Plants People Planet, 6:44–66. https://doi.org/10.1002/ppp3.10421

Rossetto, M, Yap, J Y, Lemmon, J et al. (2021). A conservation genomics workflow to guide practical management actions. Global Ecology and Conservation, 26, e01492. https://doi.org/10.1016/j.gecco.2021.e01492

Sweedman, L, and Merritt, D (2006). Australian seeds: a guide to their collection, identification and biology. CSIRO Publishing. DOI:10.1071/9780643094079

van der Merwe, M, Bragg, J, Dimon, R et al. (2023). Maintaining separate maternal lines increases the value and applications of seed collections. Australian Journal of Botany, 71(7), 406–419. https://doi.org/10.1071/BT22136

Saving threatened species at the Australian Botanic Garden Mount Annan – one ecological community at a time

In the face of ongoing biodiversity loss, the conservation role of botanic gardens continues to be a critical part of ex situ actions to safeguard against species extinctions. Since inception, the Australian Botanic Garden Mount Annan (ABGMA), has progressively built a range of conservation programs including high profile species such as the Wollemi Pine, and more recently the establishment of the internationally recognised Australian PlantBank. In parallel with these significant ex situ and scientific programs has been several decades of in situ conservation and regeneration work focused on the management of remnant Cumberland Plain Woodland (CPW) that occurs naturally at the ABGMA site.

The gently undulating topography of the Cumberland Plain region in western Sydney and its fertile clay soils were targeted for agricultural land clearing and subsequent urban development, which continues to this day. Sometimes seen as the ‘poor cousin’ when compared to the adjacent Sydney sandstone vegetation, the CPW contains amazing diversity in its rich grassy understorey layer. This grassy woodland ecosystem, which once formed a mighty forest across western Sydney, is now reduced to 6% of its original extent. As a result of extensive clearing and weed invasion impacts, CPW was listed under New South Wales legislation as a Critically Endangered ecological community in 1997.

Summertime in the woodland – showing the distinctive structure of CPW with Bursaria shrub layer and Kangaroo Grass understorey. Credit: Peter Cuneo

At ABGMA, the CPW conservation areas have an open forest structure with a tree canopy dominated by three distinctive eucalypts: Grey Box Eucalyptus moluccana, Forest Red Gum Eucalyptus tereticornis and Narrow Leaved Ironbark Eucalyptus crebra. The midstorey is largely dominated by the shrub Blackthorn Bursaria spinosa, which flowers prolifically in midsummer, attracting a huge range of invertebrates. The grassy understorey layer has a wide range of grasses, native herbs and lilies, with some of the key species being Kangaroo Grass Themeda triandra, Weeping Meadow Grass Microlaena stipoides, Blue Trumpet Brunoniella australis, Kidney Weed Dichondra repens, Pale Grass Lily Caesia parviflora var. parviflora and Common Woodruff Asperula conferta. Western Sydney is a rain shadow area, and CPW has many similarities with the drier woodlands west of the Great Dividing Range, and includes plants such as several Einadia species from the saltbush family Chenopodiaceae. CPW plants are well adapted to drought and heavy clay soils, and many are able to resprout from underground lignotubers when rainfall occurs. Set in the heart of the Cumberland Plain region, the ABGMA’s early planning during the mid 1980s recognised the importance of remnant patches of CPW, which had not been disturbed by cultivation. At this time, renowned Royal Botanic Garden Sydney ecologist Doug Benson identified areas of high species diversity, which were set aside as conservation areas. From these early days of ABGMA, Doug and his colleague Jocelyn Howell generated great interest in western Sydney vegetation through many publications and recognised that native vegetation was poorly conserved. Doug and Jocelyn also commenced a long term monitoring program in the ABGMA woodland, where they have documented changes in understorey diversity and abundance in CPW vegetation. Today, the CPW conservation woodlands have expanded since the opening of ABGMA in 1988, covering approximately 35 hectares, and are an integral part of the diverse landscape mosaic. Importantly, the woodlands are now some of the best regional examples of CPW and include threatened species Pimelea spicata and the Cumberland Land Snail Meridolum corneovirens.

The Spiked Rice Flower Pimelea spicata is a small spreading understorey shrub with white, pink tinged flowers. It is largely restricted to the clay soils of the Cumberland Plain region, growing in CPW understorey that is in good condition. Flowering occurs in spring; however, it has also been observed after favourable rainfall, where the plant is able to resprout from a small lignotuber. Due to its restricted distribution, loss of habitat and the impacts of weed invasion, the Spiked Rice Flower is listed at the state and federal levels as Endangered. The occurrence of the

Bursaria spinosa is an important habitat plant, which provides abundant nectar and pollen during summer.

Credit: Lotte von Richter

Spiked Rice Flower in the ABGMA woodland areas has long been the focus of horticultural and scientific work at ABGMA. Projects include the propagation of this species to include in horticultural displays, monitoring of local populations and a recent project at the Western Sydney Airport site requiring propagation, seed collection/seedbanking and a regional genetic study. The primary goal is to maintain this species in the ABGMA conservation woodlands through maintaining the health and diversity of the understorey layer.

The woodland areas also support a wide range of fauna, including one of the more cryptic species, the Endangered Cumberland Land Snail Meridolum corneovirens, which is also restricted to the Cumberland Plain region. This land snail has a much flatter and thinner shell than the common garden snail. Like the Spiked Rice Flower, the Cumberland Land Snail depends on a healthy diverse CPW understorey, where it lives under logs and leaf litter and eats fungi.

The management of the woodlands, particularly the understorey, comes with

Pimelea spicata is a low growing understorey plant, threatened by weed invasion and loss of habitat through urban development. Credit: Peter Cuneo

Cumberland Land

is restricted to bushland remnants in western Sydney. It lives in logs and debris at the base of trees. Credit: Lotte von Richter many challenges. The 416-hectare AGMA site is now largely surrounded by urban development, and managing CPW woodlands at this urban interface is complex due to ‘edge effects’ and weed invasion. One of the key threats to the woodland, and the threatened species habitat it provides, is African Olive Olea europaea subsp. cuspidata. African Olive is a highly invasive tree that was introduced as a hedge/rootstock plant in the mid‑1800s and ‘jumped the garden fence’ from the nearby Camden Park estate. As is the case with many invasive species, the prolific fruit of the African Olive is dispersed by birds. This has resulted in the rapid spread of this long‑lived tree throughout the Cumberland Plain since the 1980s. Bird dispersal of seed makes African Olive highly mobile in the landscape, as it establishes in ‘halos’ around large eucalypt perch site trees. It spreads from these establishment sites, and if not contained will form a dense mid‑storey canopy shading out the diverse grassy understorey layer and preventing recruitment of eucalypt canopy trees.

The

Snail

African olive forms a dense mid canopy, shading out native understorey plants and woodland regeneration.

Credit: Peter Cuneo

African Olive is a highly conspicuous invader of woodland areas, and a dedicated program established in 2000, which included volunteers, has successfully controlled its significant invasion of the key woodland areas. Less conspicuous but significant threats to the woodland are invasive grasses such as Rhodes Grass Chloris gayana and more recently, Chilean Needle Grass Nassella neesiana. Invasive grasses easily blend in with the native grassy understorey, and species such as Chilean Needle Grass can create monocultures displacing all native plants, producing thousands of seeds that remain viable for up to 15 years. Chilean Needle Grass control is achieved by physical removal and the use of selective herbicides by staff and a network of specialist contractors.

Key to maintaining diversity in grassy woodlands are appropriate fire regimes.

At ABGMA we have used spring or autumn ecological mosaic burning focusing on the understorey, which can also provide a reduced hazard risk. The natural fire regime for CPW would have included occasional higher intensity summer fires, however, this is not possible at the urban interface. Future directions include a new program of cultural burning of the woodland, which is an opportunity to engage with locally based indigenous knowledge and ecological management.

The conservation woodlands are an important component of the ABGMA landscape mosaic, which has become a regionally significant fauna habitat. With the garden transformed from a grazing property with open paddocks in the 1980s to a mosaic of woodlands, grasslands, lakes, arboreta and horticultural display gardens, it now supports over 190 bird species and is regarded by ornithologists as an outstanding site in the Sydney region. Fauna also includes a range of mammals such as wallaroos, swamp wallabies and eastern grey kangaroos.

Maintaining and developing this wider landscape mosaic is a huge and expensive task, including the control of 80 hectares of dense African Olive forest since 2009.

Wallaroos in the woodland – ABGMA is a regionally significant refuge for wildlife, which is an important part of the visitor experience.

Credit: Peter Cuneo

As the hilly areas along the eastern ridge of ABGMA are progressively cleared of African Olive, there are opportunities to conserve and expand other threatened ecological communities, such as Western Sydney Dry Rainforest, as well as CPW. Dense olive infestation sites once cleared have limited remaining native plant diversity, and their restoration often requires seed sourced from the existing woodland areas. Importantly, the woodland areas that are in good condition also provide a template or ‘reference ecosystem’ to guide restoration efforts.

In a region of intense urban development, the size of ABGMA is significant, and it is now considered a ‘green nucleus’ with much valued native flora and fauna. The biodiversity of the woodlands, combined with the established horticultural areas (focusing exclusively on native plants) provide a unique landscape, and add an important dimension to the visitor experience. Future planning will look beyond the ‘garden walls’ to ensure that native vegetation and fauna corridor connections are maintained with the Nepean River, and other local reserves as part of a regional conservation network.

The biodiversity of the woodlands, combined with the established horticultural areas provide a unique landscape

From the nursery to the field: horticulture informs translocation of Small Purple Pea Swainsona recta

Zoe Knapp1,2 , Peter Bredell1 , Emma Cook3 , Bek Hyland1, and Tom North1

1 Australian National Botanic Gardens

2 Current address: Norfolk Island Botanic Garden

3 ACT Government

The Australian National Botanic Gardens (ANBG) maintains the most extensive collection of Australian native plant taxa worldwide, coupled with vast horticultural expertise spanning over 4,000 species. Our living plant and seed collections, combined with concentrated expertise in field botany, taxonomy and evolution, seed biology, and horticulture, enable us to provide holistic solutions for plant conservation, from wild sourced plant material collection to propagation of plants for translocation. Here, we present a case study that demonstrates how establishment of ex situ plant populations and associated horticultural knowledge can inform long term recovery in situ.

Since the 1980s, the ANBG has been increasingly involved in the propagation of threatened species as part of multi agency conservation projects. The ANBG has an important role supporting plant conservation in other Commonwealth terrestrial reserves managed by the Director of National Parks. Its location in Canberra also positions the ANBG as the primary horticultural facility for plant conservation in south east New South Wales, for example geographically (proximity to field sites for plant material collection, and delivery of propagated plants), horticultural capacity (expertise, specialised infrastructure), and local climatic conditions required for propagation and cultivation.

One of our most rewarding projects has been a long standing collaboration with the ACT Government’s Office of Nature Conservation to rebuild local populations of the Small Purple Pea Swainsona recta. The Small Purple Pea is a slender, erect perennial forb in the family Fabaceae. Once considered widespread in grassy woodlands across south eastern Australia, the species is now restricted to relatively small and fragmented populations in NSW and the ACT and is listed as Endangered under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), the Nature Conservation Act 2014 (Australian Capital Territory) and the Biodiversity Conservation Act 2016 (New South Wales).

In 2023–2025, the ANBG will provide 1000 Small Purple Pea plants for re wilding at crucial sites in the ACT. However, our involvement extends beyond mere plant supply (albeit a challenge on its own, as noted below); we engage in all phases of conservation projects, leveraging our expertise and learning from others. Below we outline some of the broader contributions that botanic gardens horticulture can make to in situ plant conservation.

Credit: ANBG

Seed collection from wild populations

We collect seeds from across all wild populations to capture as much genetic diversity as possible. Through close coordination between our nursery and the ANBG’s National Seed Bank we are facilitating research into seed dormancy and germination cues, and conservation banking requirements for the species.

Propagation and cultivation techniques

Many species propagated in the nursery have either never previously been propagated or are notoriously difficult to propagate. Our horticulturists have developed efficient propagation methods for the Small Purple Pea, which is labour intensive to grow. Seeds sown in the nursery germinate sporadically over a period of up to nine months, requiring ongoing pricking out and potting up of new seedlings. The development of a specialised growing medium has dramatically improved cultivation success in the nursery. Flower buds are removed from plants in the nursery for genetic reasons (discussed below) and to allow plants to focus energy on root development. The species’ deep, fleshy tap root appears to be critical to its survival in the wild, allowing plants to recover after exposure to, for example, grazing, fire and drought. In the nursery, plants grown in deeper tubes have a substantially more robust and well developed root system than those grown in standard forestry tubes.

Purple Pea roots quickly reach the bottom of the deeper pots.

Credit: ANBG

Small Purple Pea plants ready for re wilding at a recipient site.

Small

Seed production

In 2016, seed from several Small Purple Pea populations in the ACT region was germinated and planted in the ANBG’s dedicated seed production area (SPA) in a scientific design intended to maximise genetic diversity of resulting seeds. Each year, horticulturalists have bagged and collected seed from these plants, which is then passed to the National Seed Bank for cleaning, viability assessment and banking. This alleviates pressure on wild populations, provides easy access and enables research and observations on the species. Interestingly, seeds collected from the SPA appear to have much higher germination rates than seed collected from wild plants, although results are anecdotal.

Ex situ ‘insurance’ collections

Small Purple Pea in the seed production area, with seed collection bags. Credit: ANBG

Our scientifically documented seed bank and living collections, most of which are linked to herbarium specimens, serve as an invaluable resource for research, genetic preservation and as backup populations for future recovery efforts. The seed bank and living collections include over 300 threatened species listed under the EPBC Act, and many more that are protected under state legislation, and/or known to be rare or threatened.

Maintaining genetic differentiation

Concurrently with this project, the ANBG partnered with NSW Local Land Services (Central West and Central Tablelands) to assist with recovery actions for the Small Purple Pea in NSW. Since there is evidence of genetic differentiation between the northern (central NSW) and southern (ACT and southern NSW) populations (Buza et al., 2000), we remove all flower buds from plants in the nursery to prevent cross pollination between genetically distinct populations.

Cultivation informs planting requirements and post-planting care

Insights from nursery cultivation inform optimal planting practices. For example, we’ve observed the following for Small Purple Pea:

• Plant age: Plants require at least 18–24 months from germination to develop a sufficiently robust root system to survive translocation.

• Planting hole size: Growing plants in deeper tubes also means digger deeper holes for planting. However, any investment in facilitating the successful development of a deep tap root is likely to improve translocation success.

• Timing of planting: Spring and early autumn are suitable planting timeframes because plants are actively growing and more likely to successfully establish post translocation.

• Plant spacing: The species does not tolerate physical crowding, and translocated plants have been intentionally spaced, and mulched to inhibit the growth of competitors near the plant.

• Post-planting care: A fine quartz gravel mulch (<5 mm diameter) was applied to translocated plants to 30 cm diameter around the base of the stem. This will help to retain soil moisture and deter weeds around the base of the plant. This method has been applied to half of the translocated plants (randomly allocated) to experimentally test whether the treatment influences post translocation survival.

• Seed treatment: Seeds are physically dormant and require heat shock to alleviate dormancy prior to sowing. This was achieved by placing seeds in hot water (95 °C) for 3 minutes followed by immediate transfer to cold water (4 °C) for 1 minute, and then repeated. Seeds were then rinsed under room temperature water before soaking in room temperature water for 1 h to allow seeds to imbibe.

• Pest and disease susceptibility: Translocated plants were protected with a wire mesh plant guard because plants in the nursery were selectively susceptible to rodent predation. In the nursery, caging plants to prevent rodent herbivory resulted in powdery mildew and a scale infestation likely due to overcrowding, reduced airflow and exclusion of beneficial predators. These problems are considered unlikely in open translocation sites.

Horticultural experimentation informs translocation methods

Nursery based experimentation can inform better translocation methods. Nursery trials in this case have resulted in the development of an optimised growing medium leading to healthier, more vigorous plants, the use of deeper tubes to facilitate optimal root development, a better understanding of how and when to translocate plants, and the recognition of the importance of post translocation care.

Small Purple Pea growing in the nursery.

Credit: ANBG

Small Purple Pea growing in different pot sizes.

Credit: ANBG

Combining our expertise for better outcomes

ANBG is increasingly moving away from a restricted role as plant supplier, towards a model of involvement in conservation projects from planning to post translocation. This helps to combine our multi agency expertise and skills as outlined above to achieve better conservation outcomes.

Next steps

The seed stores and the plants produced in the nursery, with the resulting ecological knowledge about the species, are being used in translocation efforts to increase the size and vigour of wild populations. The Office of Nature Conservation has rigorously planned the Small Purple Pea translocations, incorporating experimentation and data collection to inform future translocation success. It will be very rewarding to see the plants go back into the wild, and hopefully result in genetically diverse, self sustaining populations.

Joining forces: aligning ex situ and in situ threatened plant conservation programs to support regional priorities

Emma

Simpkins, Senior Regional Advisor Flora at Auckland Council and Ella Rawcliffe, Botanical Records and Conservation Specialist at Auckland Botanic Gardens

Emma Simpkins

Ella Rawcliffe

Botanic gardens play a pivotal role in the conservation of threatened plant species worldwide. Their significance lies not only in preserving plant diversity ex situ but also in aligning their efforts with existing in situ plant conservation programs. By integrating botanic gardens’ conservation efforts with in situ programs, botanic gardens enhance the effectiveness of conservation actions, facilitate the exchange of knowledge and resources, and promote holistic approaches to plant conservation.

In Auckland, regional threatened plant conservation is led by the Auckland Council Environmental Services (ES) team. In the last 18 months, ES has been working on the regional threat classification of plants, identifying the pressures to each threatened species, and identifying multiple locations where these threatened plants can be managed in situ across their suite of pressures while maintaining and enhancing populations for at least the next 50 years. This has allowed us to identify those species that will be challenging to support in situ with the current tools and technology we have available. It was only natural to draw on the skills and expertise of Auckland Botanic Gardens (ABG) to work in partnership on these species to support threatened plant conservation in a strategic way.

The collaborative partnership between ES and ABG has been identified as critical to achieving regional and national native plant conservation outcomes, combining and building skills, knowledge, resources, partnerships and capability. These departments have clear responsibility

and mandates to work in their respective fields — ES with in situ conservation and ABG with ex situ conservation. Working in partnership to align existing and future projects will build capacity to deliver the goals set for us through regional, national and international plans/policies.

Auckland has approximately 357 threatened species, which is almost half of the (identified) native flora in the region (Simpkins et al., 2022). A massive 224 species have been identified for potential ex situ conservation. These species have been identified based on one or more of the following factors:

• our inability to manage the key pressures, e.g. climate changes, and habitat limitations for in situ populations, based on the current conservation tools and technologies available

• species that are only found at a single location in Auckland and are therefore at risk of loss due to their limited distribution

• the highest regional threat status.

Special species this partnership has been actively working on to survey, research, seed collect and/ or propagate include:

• Korthalsella salicornioides, a native leafless mistletoe that is regionally at risk (declining) and requires research into propagation techniques for establishing new populations. In situ management has involved planting new hosts under existing hosts that are in poor health and have declined rapidly in the last few years. This species is at a limited number of locations in the region, and our hope is we can translocate it to suitable habitats if we can master the technique of ‘planting’ it (which we have done for another native mistletoe, Ileostylus micranthus). We collected 60 seeds and planted them onto six hosts at the ABG, which can be monitored in the nursery as they establish.

• Lophomyrtus obcordata, or rōhutu, highly threatened due to Myrtle Rust and is regionally vulnerable. The pressure of Myrtle Rust and pest animal browsers means we see little recruitment in the wild and this species could go extinct without conservation efforts. Fungicide treatments on in situ plants have enabled one population to produce seeds, which have been grown on and become an ex situ collection. The ongoing maintenance of this collection is more time and resource demanding than other collections, but these actions are critical to its ongoing survival.

Ella carefully placing seeds of Korthalsella salicornioides in the fork of a host branch of Leptospermum scoparium and marking the site with white out to ensure we can find them again. Credit: Emma Simpkins

• Pomaderris rugosa, regionally vulnerable and found in open scrub on clay and impoverished soils. Although this plant is on some offshore islands in Auckland, it exists only in one location on the mainland and the population is incredibly small. Over the last five years, we have seen plants dying each year. The remaining plants are growing in an exotic gumland and therefore cuttings and seeds have been taken to establish an ex situ collection, as well as to propagate plants to translocate to a more appropriate native gumland habitat.

• Thyridia repens, regionally endangered Native Musk, found in saltmarshes and estuaries where it is permanently damp. In situ management of exotic weeds is undertaken 2–3 times

(left to right) The site of Lophomyrtus obcordata growing on Awhitu Peninsula in Auckland, where in situ fungicide applications have allowed this species to produce fruit. The resulting seeds were grown by a local community then transported to Auckland Botanic Gardens for ex situ conservation. A small but critical ex situ collection of Lophomyrtus obcordata in the nursery. Credit: Ella Rawcliffe a year to maintain an open habitat for this species, and trials of plugs for translocations are scheduled. This species has recovered slowly from being underwater after nearly a year of rain, raising concerns about its persistence long term in situ.

(left to right) Pomaderris rugosa starting to bud during a survey to determine the population size and extent, prior to a seed collection trip. Cute little flowers make spotting Thyridia repens in the saltmarsh easier. Credit: Emma Simpkins

We are also exploring introducing Scandia rosifolia, Eleocharis neozelandica and Leptinella rotundata into ex situ collections. Relationships between iwi and landowners are currently being developed as part of the in situ work, as well as translocation plans for some species. ABG will be brought into these conversations as the plans develop. We are looking forward to future opportunities to bring more threatened plants into ex situ conservation while aligning with in situ priorities.

Hortis – the plant record platform selected by BGANZ

Worried that record keeping is taking up too much time? Struggling with plant names, and feeling frustrated with an overwhelmed IT team? Want to increase your impact by making your collection public? These are exactly the challenges we have been solving with Hortis.

Since 2020, we have welcomed new BGANZ members to the Hortis community to help them with their plant records. Fast forward to 2024, we have almost 30 BGANZ gardens on a journey towards more efficient, accurate, and always accessible plant records, no matter their institution’s mission.

With the recent release of Public Sites, you can now increase your collection’s reach and impact by sharing it with visitors online. Together with Shared Taxonomy, the quality of your data is increased with access to all plant names, IUCN Red List status, and native distribution at your fingertips.

If you are ready to start a new chapter for your collection, then we have a special offer exclusively for BGANZ members: doubled editing capacity for the first year of your subscription

To get started, request a trial, or to simply learn more, contact us today: info@hortis.com

Perennial management and garden design

Meg Awatea Spittal, Horticultural Apprentice, Auckland Botanic Gardens, Aotearoa New Zealand

A BGANZ Young Member Award 2023 Report

Meg received the BGANZ Young Member Award last year, at the start of her horticultural career as a 24 year old first year apprentice at the Auckland Botanic Gardens (ABG). The Awards Selection Panel was impressed with her passion for sustainable garden design and eagerness to further her knowledge in this area. She applied with the aim of using the award to further her long term dream of becoming a collections curator.

Background

Meg Awatea Spittal

Since I was a child, the growth of perennials has always interested me: being able to watch a single plant appear in spring, become a beauty through summer and then finally return to the ground in winter, seemingly dead, only to do it all over again the following season. Now, I want to know as much as possible on how to make these plants happy in a changing climate, as well as creating a border that is exciting and appealing.

Sadly, in New Zealand, we are seeing the closure of many independent plant nurseries, leaving only larger commercial ones. With this, many heritage and uncommon perennial cultivars are becoming impossible to purchase. It is a difficult and expensive exercise to get new plant material into the country as biosecurity is rigorous to protect our native flora and fauna. Therefore, any existing cultivars that are present in New Zealand, such as those in botanic gardens, need to be conserved so they are not lost for good.

In 2023, I was fortunate enough to be awarded the BGANZ Young Member Award. I used the money I received to help pay for two online courses on Planting Design with Perennials and Perennial Management, The Piet Oudolf Way, presented by Dr Noel Kingsbury.

Learnings

There are a lot of moving parts to create a perennial garden. For example, what is the condition of the garden? Which plant species will become thugs, aggressive and domineering, and are therefore best avoided? What plants will thrive without dominating? Will the garden have year round interest, with succession through the seasons? Is there a colour or texture repeated to unite the garden? Can the plants be lifted easily and divided each year to replenish your stock? The list goes on…

You need to understand the type of perennial you are dealing with when selecting plants for a perennial garden, for example, their life span and whether they have a spreading habit that is good for propagating clumps off, but may be aggressive. Once you have a good idea of how the species grows, you can ascertain its place in the garden. Some plants spread too quickly, like the asters I’ve seen growing in the Rose Garden Pergola at the ABG. They rapidly fill the space with great impact but tend to grow through their neighbours and outcompete them, requiring us to dig them out by the bucketful. Perhaps this is one plant that is better placed in a garden with larger plants that it will struggle to dominate, and in a spot that is easy to access so that you can pull up any bits that stray from its designated area.

Once

you have a good idea of how the species grows, you can ascertain its place in the garden.

Your planting needs to be intentional, with a goal or focus on what you’re wanting the garden to ‘say.’ This will be a guide to keep you on track while changes over the seasons determine what plants do well, and what plants do not. It is a constant battle of editing, seedling removal, gap filling and replacing losses. It involves using a critical eye to re assess the performance of plants, seeing if they would benefit from a change in position, or deciding that it isn’t a plant meant for your garden at all.

The original idea around perennial maintenance was to cut back everything to the ground once plants stopped flowering, giving a tidy yet barren garden over the winter months. Now, gardeners want to celebrate the shapes and forms of dried seed heads and foliage. This new perennial movement gives winter interest in the garden, like the upright umbels of Yarrow Achillea filipendulina and Sedum spectabile ‘Autumn Joy’ or the soft fluttering blades of Miscanthus sinensis ‘Gracillimus.’

As these dried statues degrade over winter, or just before spring, the plants can be cut back as required to give sufficient light to the new season of growth. One tip I particularly loved from these online courses was to cut up the removed top growth and lay it on the ground around the plant. This acts as a natural mulch layer, mimicking what would happen in nature each season, allowing the nutrients that remain in green stems to return to the soil and providing a great home for insects. Unsurprisingly this would appear ‘messier’, but solves many issues like green waste removal,

Cynara cardunculus in the Perennial garden at ABG. Credit: Meg Awatea Spittal

bringing mulch on site and adding feed to the garden.

Dried seed heads of Sedum spectabile ‘Autumn Joy’ (left). Seed heads of Miscanthus sinensis ‘Gracillimus’ in the autumn morning light (right).

Credit: Meg Awatea Spittal

Plants perform best in an environment like the one in which they evolved. You wouldn’t plant Rosemary Salvia rosmarinus on a pond margin and then constantly try to dry out the soil just to keep the plant happy. Rather, you would plant it in a drier spot with free draining soils and lots of sun. Matching perennials to their natural habitat reduces the need for irrigation and feeding, which reduces environmental impacts. By gardening in tune with nature and selecting plants that naturally coexist, you are creating stable plant communities that are artificial versions of natural ecosystems, thus requiring lower maintenance.

What’s next?

Taking these courses has been a great addition to my career, and reaffirmed my thoughts and beliefs around perennial management and garden design. They have been invaluable to my approach to gardening from daily workings to overall standards.

I will continue striving to learn more, attending as many conferences and talks as I can around garden design as sustainability. I have had the good fortune to attend two talks by Jo Wakelin about her water conscious garden design in Cromwell, Central Otago. It is now an aspiration to visit her garden, to see it in person and gain a greater understanding of matching plants to a low rainfall climate.

I also aim to write articles for the Friends of the ABG newsletter to raise awareness of vulnerable cultivars, and to advocate for the Friends of the Gardens to propagate highlighted plants at the Friends Nursery for their weekly public plant sales.

Seen at the back of the Native Plant Ideas garden, where garden curator Pippa Lucas leaves fallen hedge clippings on the ground to rot down and act as a natural mulch.

Credit: Meg Awatea Spittal

Hidden assets

Lorraine Perrins, former staff member and current volunteer, Royal Tasmanian Botanical Gardens

Botanic garden nurseries have been referred to as the ‘engine room of everything’ (BGCI, 2022), highlighting the fundamental contribution they provide to botanic gardens’ operations. Having spent the bulk of my career working in botanic garden nurseries, I wholeheartedly agree.

As the world grapples with the continuing loss of plant diversity, we are witnessing an increasing demand for botanic gardens to rapidly expand their commitment and capacity to mitigate this loss. The investment in building a global network of botanic garden seed banks has resulted in significantly more threatened species being conserved as ex situ insurance against extinction. This has led to many botanic garden nurseries actively participating in what is conventionally termed ‘conservation horticulture’, for example, supporting seed banks by growing threatened plants in seed production areas/orchards to increase quantities of seed that can be harvested from difficult to access species. It has also led to increasing requests to grow species for reintroduction or translocation programs, as organisations managing these projects appreciate the specialist skills required to grow species new to cultivation.

The investment in building a global network of botanic garden seed banks has resulted in significantly more threatened species being conserved as ex situ insurance against extinction.

Author, botanist and previous Director and Chief Executive of Royal Botanic Gardens Victoria (RBGV), Dr Tim Entwisle, likened conservation horticulture to intensive care units when describing the response by the RBGV ‘Plant Rescue and Care Unit’ to the 2019–2020 catastrophic bushfires (Entwisle, 2023), and I would broaden that analogy. Botanic garden nurseries and seed banks are akin to entire hospitals, providing care services for threatened flora by way of emergency intervention and triage; plant paediatrics; incubation spaces for identifying future research opportunities; as well as palliative/aged care of exceptional plant species. Only when considered in this way can the variety of skills, expertise and resources required to maintain the ‘engine room/hospital’ be fully appreciated.

Seed germination testing at the Tasmanian Seed Conservation Centre, located in the Royal Tasmanian Botanical Gardens. Credit: James Wood RTBG

Botanic garden ex situ collections are often located away from publicly accessed areas, usually to mitigate potential biosecurity and theft risks, but also because they are primarily insurance collections and are not being grown for display. Packets of seed in a freezer are not particularly engaging, likewise monocultured blocks of one species grown for seed harvest usually lack an attractive horticultural aesthetic. The value of these ‘hidden assets’ cannot be underestimated; however, they suffer from being ‘out of sight, out of mind’ and are often overlooked in attracting adequate resourcing. Many suffer boom and bust cycles of infrastructure maintenance and investment, compounded by competing demands for nursery space and resources from non‑conservation programs.

I would also argue that it is not only the threatened plant collections held within these facilities that are priceless. The dedicated, highly skilled professionals who care for them are also often overlooked, hidden assets. These horticulturists face many challenges when determining the germination or cultivation requirements of individual species, usually being grown outside their natural range. Other drawbacks in growing monospecific stands of species as seed orchards are the increased risk of pest and disease attack; the required suite of pollinators may not be present; and risks associated with pollen cross‑contamination. Being able to navigate these issues and remedy them effectively is critical, but not always easy.

Diligent record keeping is paramount for all ex situ collections to identify and track individual progeny and ensure genetic diversity is maintained over time. Inadequate standards will compromise the conservation value of the collections. An absence of skilled staff managing these collections can result in impoverished collections primarily consisting of horticulturally robust and ornamental species. Investment must be made to attract, train and retain staff to build the depth of knowledge critical to ensuring conservation programs are successful.

A hidden asset is an asset that is not stated or is understated. The economic value of most botanic gardens is often quantified by the number of visitors they attract via recreational tourism. What if botanic gardens were also to provide a measure of the impact their seed banks and nurseries contribute regarding practical conservation activities and our understanding of plant science?

Harvesting seed from the critically endangered species Davies’ Waxflower/St Helens Waxflower Phebalium davesii at the Royal Tasmanian Botanical Gardens nursery.

Credit: RTBG

By documenting, and importantly publicly reporting, how collections are used by third parties, a bigger picture of the importance of the critical services and resources that botanic gardens provide can be emphasised and understood, both within the organisation but also among potential funders and the broader community. Some larger botanic gardens do highlight the use of their collections in annual reports but often this information can be overshadowed by events or other activities. I would argue that the use of collections in our understanding of plant diversity and its conservation into the future needs to be proclaimed at every opportunity.

It has been stated that ‘Gardens have the expertise, tools, facilities, and networks in place to be the strongest force for plant conservation – they just need the resources to match the global need’ (Westwood et al., 2021). Understating the importance of these ex situ collections and the experts who maintain them de values our institutions. By simply adjusting our approach to highlight the critical contributions that our seedbanks and nurseries provide to conservation horticulture, we can ensure that they no longer remain ‘hidden assets’.

Royal Tasmanian Botanical Gardens staff assessing a seed orchard of the threatened species, Eastcoast Paperdaisy Xerochrysum bicolor.

Credit: James Wood RTBG

The role of botanic gardens in fighting the extinction battle

Matthew Nicholson, volunteer editor, Notes from the Nursery

Iamamemberofthenurseryteaminabotanicgardenandalso workasabushrestorer.Please get intouchifyouwouldlike to contribute tothissectioninthefuturebyemailingmeat nicholson20@hotmail.com.au.

As the world grapples with an unprecedented biodiversity crisis, the role of botanic gardens in shaping conservation policy, preserving genetic material through seed banking, and educating the public in this area has become increasingly important. This article delves into these crucial functions of botanic gardens, elucidating how their work transcends traditional boundaries to impact conservation in profound and lasting ways. Botanic gardens are often seen as quiet repositories of plant knowledge, but they provide a valuable resource from which aspects of public policy concerning conservation are derived. This knowledge base consists of data collected from seed collection and conservation sites. It provides snapshots of species’ increase or decline and makes the botanic garden ‘a driving force’ behind plant conservation (Westwood et al., 2020).

According to a 2017 study conducted by the University of Cambridge, 41% of plants classified as ‘threatened’ are contained within the world’s botanic gardens. Botanic gardens are thus ‘on the front lines of biodiversity conservation’ (Ren & Antonelli, 2023). The development of botanic gardens was ‘driven by the basic needs of human society’ up until the present stage of their development (Li et al., 2023). Li and colleagues discovered a strong correlation between the establishment of the world’s first botanic garden in Germany in 1593 and global social and economic progress ever since. The initial ‘exploration’ stage of botanic gardens served to establish collections of medicinal and edible plants. The ‘classic’ stage was precipitated by the invention of the binomial system of nomenclature, devised by Carl Linnaeus in 1753, which facilitated the categorisation of plant species in botanic gardens. Li and colleagues charted the subsequent development of the ‘colonial tropical’ botanic garden in the modern era (1765–1945), up to and including the ‘gardening and specialised’ botanic garden stage, and finally the rapid post war development of the ‘scientific and conservation’ stage of botanic gardens. They show how botanic gardens have evolved from collections of medicinal plants to multipurpose institutions, involved in ‘scientific research, plant diversity conservation, education, and dissemination of knowledge’ (Li et al., 2023).

Matthew Nicholson

Experts from botanic gardens often work with government or other bodies on a consultative, volunteer, or advisory basis.

Their involvement is evident in the activities and aims of organisations such as BGANZ and Botanic Gardens Conservation International (BGCI). Botanic gardens, such as Botanic Gardens of Sydney (BGoS), which are part of the NSW State Government’s Saving our Species program, provide a valuable resource for the preservation of the species in question.

The many Friends groups in Australia, New Zealand and worldwide also make an important contribution to threatened species conservation; for example, the Friends of the Australian National Botanic Gardens (FANBG) in Canberra offer student scholarships that support honours, masters, or PhD candidates who ‘engage in collaborative research projects that bring direct benefits to the ANBG’ and align with its objectives (FANBG, 2023). The FANBG scholarships aim to ‘enhance knowledge of and the conservation’ of Australian plants. The Friends of the Royal Botanic Gardens Melbourne has a trust fund, which supports a research grant and staff scholarships. Some botanic garden Friends groups, such as the Friends of Auckland Botanic Gardens, the Friends of Wollongong Botanic Garden, and further afield, the Friends of Edinburgh Botanic Gardens, Friends of the Royal Botanic Gardens, Kew, and Friends of the Botanic Gardens at the University of California, Berkeley, offer internal scholarships that enable staff to visit other botanic gardens to further their career prospects and gather information pertinent to their home botanic garden. This information and networking may be aimed at caring for or extending a collection of rare and threatened species or creating a section dedicated to rare and threatened genera. Aspects such as specific habitat requirements, genetic diversity, propagation techniques, pest and disease management, or ideas about public education surrounding these rare and threatened species may be gleaned from these trips and visits.

One prominent threatened species success story is that of the Wollemi Pine Wollemia nobilis, a coniferous species discovered in Wollemi National Park in 1994. It was subsequently bred by tissue culture and brought back from the brink of extinction despite its low population size and high susceptibility to pathogens such as Phytophthora cinnamoni. In 1994, it was cultivated by the Adelaide Botanic Garden, South Australia, the Royal Botanic Garden, Sydney, Mt Annan Botanic Gardens, and Mt Tomah Botanic Gardens. In 2001, a comprehensive paleoenvironmental reconstruction of the distribution of Wollemia was conducted by Kershaw and Wagstaff (2001), with particular attention paid to how Araucariaceae responded to Australian continental drift, the evolution of angiosperms and the associated changes in fire regimes. It has been challenging to study the breeding system of W. nobilis due to a lack of reproductive material, but ‘recent female cone production in cultivated plants has enabled some manipulations’ and provided access for ‘repeated preliminary observations’ (Australian Government, n.d.). However, as the challenge of global warming increases, it poses yet another threat to the wild population. Izzard’s article (2023) about conservation efforts surrounding W. nobilis recounts the Black Summer fires of 2019–2020 when the stand was saved just in time by firefighters and airborne water tankers.

A new metacollection of this species comprises a global collaborative effort and involved an initial citizen science survey in 2019. Then, shipments of ‘210 young Wollemi Pines representing the full diversity of the wild population’ were sent to botanic gardens in the United Kingdom, Ireland, Europe, Australia, and North America – places selected to provide ‘the best possible long‑term conditions for a resilient and global metacollection’ (Izzard, 2023). The BGoS sent each botanic garden a micro‑population of six plants, ensuring ‘plenty of genetic diversity’ (Izzard, 2023).

In a recent article, Ostgaard (2024), the Director of Botanical Solutions for Species360, comments that the reason behind the huge gap in knowledge of the content of one‑third of the world’s

botanic gardens is ‘due to the poor adoption of computerised plant record systems’, and advocates for the use of plant collections platforms, specifically Hortis (which he founded), to address this issue. He also advances the case for collaboration between different botanic gardens, which can ‘help increase genetic diversity…[and create] a valuable source of material’, as a single plant in one garden lacks the genetic diversity ‘required for practical conservation purposes’.

Research conducted by botanic gardens and systematic botanists can be controversial, as evidenced by papers such as the one by Wilson et al. (2022) on the conservation of the Critically Endangered Hairpin Banksia Banksia vincentia. They write that the number of species of Hairpin Banksia has been overestimated, and suggest that incorrectly applied taxonomy can gradually erode species resilience by an over‑emphasis of genetically poor populations. This has the knock‑on effect of ‘masking others that are more genetically diverse’ – poorly applied taxonomy can cost time and money in the misdirection of conservation resources, thereby concentrating on genetically poor populations, while more genetically diverse populations remain neglected. This is a lesson for conservationists worldwide to get the taxonomy right before launching into a conservation program. The article and its conclusions are certainly worth reading in full.

In addition to germplasm conservation and seed banking, botanic gardens play a vital role in habitat restoration and reintroduction programs by partnering with groups such as Landcare and Bushcare, which rely on armies of volunteers, as well as working with environmental contractors and subcontractors who maintain natural areas. Through this intimate knowledge of endemic species, botanic gardens can, directly and indirectly, influence public environmental management policy through collaborative processes. Their expertise in biodiversity and conservation positions staff

Wollemi Pine at the Australian Botanic Garden Mount Annan. Credit: Glenn Smith

at botanic gardens to influence and inform decision makers in areas of public policy. There is currently a collaborative project around the restoration of key ‘Big Scrub’ tree species to prevent inbreeding and protect them from emergent threats (Big Scrub Rainforest Conservancy, n.d.). This project is being conducted by Big Scrub Rainforest Conservancy in collaboration with the BGoS’s Research Centre for Ecosystem Resilience. It involves genome analysis of 10,000 leaf samples from 60 tree species across 30 populations to ensure the best possible genetic diversity for the Big Scrub region, as well as planting of a seed bank plantation, and harvesting of genetically optimal seed

Volunteer planting day at Stream Hill Landcare group, Kembla Grange. Credit: Tracee Lea

by Firewheel Rainforest Nursery. This seed will be propagated into planting stock for rainforest restoration contractors. As of 2022, the project has planted 250,000 individual trees over 80ha in the Big Scrub, located in north‑eastern NSW.

Plant conservation can aid sustainability by protecting ecosystems, maintaining biodiversity and safeguarding clean air and water, climate regulation and pollination. Botanic gardens not only provide spaces for biodiversity as far as providing habitat, food and shelter for native fauna, but also provide excellent learning spaces for children and adults who have a vested interest in absorbing the benefits these spaces provide and the training programs botanic gardens education centres offer in the conservation area, among others.

Botanic gardens provide valuable data for conservation-related public policy.

Policy and decision makers can see the concrete effects that botanic gardens have on endangered species, such as the Wollemi Pine. Botanic gardens promote research and conservation by, for example, offering workshops, lectures and guided tours to educate the wider public about their collections and conservation efforts regarding threatened species, collaborating with universities and research institutions on studies that advance knowledge in plant conservation, and maintaining seed banks and living collections of rare, threatened, and endangered plant species in the effort to preserve genetic diversity. They also collaborate with other gardens and stakeholders in the propagation and reintroduction of threatened species into their natural habitats. Indeed, as Blackmore argues, their future role should be ‘nothing less than shaping and contributing to a sustainable future for humanity’ (Blackmore, 2017).

News from BCARM, the BGANZ Collection and Record Management group

Sheree Parker, BCARM Chair and Supervisor, Geelong Botanic Gardens

In March we held an open‑style workshop addressing some of the questions sent in prior to the meeting. Using these questions, we picked out some common themes, which looked at collaboration and exchange of ideas, plant material, expertise, or other areas in which we can offer our help or support.

Other priorities for our gardens were advocating for our collections, how do we reach those non‑ planty people! and ensuring horticultural staff are able to be horticulturalists without the continual ‘mopping’ up from pressures put on the collections from external sources.

Ex situ conservation was another topic of interest, which tied in with better exchange of material and looking at how we work within state guidelines to safeguard threatened species, and adapting ourselves to overcome legislation that may hinder efforts. Also, how to grow our opportunities to create viable pathways to increase our plant diversity and continue our involvement in conservation programs.

Future directions that came out of the workshop –

• Creation of a database of garden exchange (think broad ways in which we can help each other)

• Creation of a map or datasets of botanic gardens in Australia and New Zealand to determine climate change environments of the future, allowing these gardens to be considered to house at‑risk species in ex situ collections

• advocating for our gardens: developing a communications pack to help with addressing the importance of living collections and the broader societal value of botanic gardens

• making exchange of material easier both nationally and internationally.

BCARM held a webinar in May as part of Botanic Gardens Month professional development events, ‘Advocating for our gardens – The hidden pressures on our living collections.’ The webinar delved into the approaches to events held within our botanic gardens and the strategies employed by gardens in supporting their living collections. It explored various event approaches, our means of supporting them, and the associated benefits and expenses incurred in caring for and curating our living collections throughout the event lifecycle. We investigated strategies for managing staff and how they assess and handle this impact, addressing the sustainability and pressures exerted by events on our landscapes.

Ultimately, we aimed to demonstrate how such events cannot only enrich our understanding of botanic gardens but also raise awareness of the significance of our living collections, thereby fostering appreciation and support for our botanical endeavours.

Our presenters were Damian Wrigley, Manager, Living Collections and Conservation at Botanic Gardens of Sydney, Barbara Wheeler, Curator, Auckland Botanic Garden, John Sandham, Collection Development Officer, Botanic Gardens of South Australia, Ali Smith, Technical Officer & Peta Lewis, Assistant Curator Horticultural displays, from Kings Park, WA.

The BCARM Forum in July will be around the idea of ‘Conservation and long-term sustainability of our living collections’. We are looking at exploring funding, grants, succession planning and how we allocate our resources for our living collections. We will also address developing connections and building our networks for now and into the future. The online forum will be held on 30 July at 10am AEST. Our guest presenters are Doug McDougall, Ground Manager, Olive Pink Botanic Garden and Marie Velthoven, Horticulturist Team Leader, RBGV Cranbourne.

The forum in September is still a work in progress, but we are looking at professional development for our staff who work with living collections. For example, assessing if there is a need for a more formal process for exchange of people around our network. We are also looking at up and coming horticultural staff and their take on living collections. We will close out the year in October with a final forum to be announced.

BCARM is also involved with the Australian Network for Plant Conservation to help deliver workshops around Myrtle Rust and the care and implications this has on our living collections. Designed for the practitioner, these workshops help to increase networks among gardens and are a place to swap ideas and tips on the management of Myrtle Rust in their gardens.

If you are interested in joining BCARM, please email me at SParker2@geelongcity.vic.gov.au.

We speak for the trees. The role of arborists in botanic gardens and the value of our trees

Ian Allan, Chair BARB and Supervisor Natural Areas & Arboriculture, Blue Mountains Botanic Garden, Mount Tomah

For most visitors to our amazing botanic gardens, the trees frame their experience. From picnicking and taking respite from the hot summer sun in their shade, frolicking in fallen autumn oak leaves, pondering ancient lands where trees like the Wollemi Pine were once common, or watching the birds in hollows atop towering eucalypts, people connect with our trees in deep and long lasting ways. Often, they are the most dominant plants in our landscapes — their presence is undeniable — yet many people are not aware of the benefits trees provide them, and even fewer people know who looks after our trees and how we do it.

Our tree collections and the naturally occurring trees provide a vast array of benefits to society and the environment. Public awareness of the importance of trees has seen a massive upsurge in recent years, with even primary school aged kids learning about carbon sequestration, ‘forest bathing’, habitat trees and the efforts to save the Wollemi Pine from extinction.

As arborists and tree managers in botanic gardens, we have committed ourselves to the life of the Lorax — speakers for the trees. As the BGANZ Arboriculture (BARB) Professional Group, we are committed to advocating for both the trees AND the arborists. Across our network of highly qualified and expert arborists, we put our skills and knowledge to work daily to ensure our trees, and the benefits they give us, can continue to grow and be maintained sustainably for generations to come. We garden our trees, but we also do a whole lot more …

Just like the shrubs and lawns in our gardens, our trees need care and maintenance (as some of the longest living plants in our collections that provide the most benefits, one could make the case they deserve even more care!). Our experts mulch our trees to ensure they have healthy soil to support their growth, we carry out decompaction works using specialist, science based techniques, we do all types of pruning, pest and disease management, planting, and on top of that, we manage comprehensive living collection record keeping systems that set us apart from your average garden or park.

Many people know that arborists prune and remove trees due to risk, and of course our arborists do that too. Some of the arborists in our network are highly qualified, leading experts in managing tree risk. I like to think this is so we can educate people on the proportionally low risks from our trees and balance those risks with the amazing benefits our trees provide. When we do that well, we can get on with the tree management work that is unique to arborists in botanic gardens.

Many of our experts are qualified consulting arborists. They play important roles in guiding their organisations in balancing the pressures and impacts on our trees from the increased use of our gardens, and the development of facilities and infrastructure, to ensure the benefits and value of our trees are maintained.

At Kings Park and Botanic Garden in Western Australia, BARB Treasurer/ Secretary Chelsea Payne and her team of arborists are playing a key role in the biosecurity response to the arrival of a wood boring pest, Polyphagous Shot Hole Borer, that threatens to heavily impact Australia’s trees and our urban forests.

At Royal Botanic Gardens Victoria, BARB Committee Member Peter Berbee and his colleagues are involved in the Global Conservation Consortia for Quercus. They are building their Oak conservation collection and distributing it throughout the BARB

network to secure wild sourced oaks that are incredibly difficult to import into Australia (to read more about this, click here).

At Botanic Gardens of Sydney’s gardens, arborists including BARB Committee members Matt Coyne from Royal Botanic Gardens Sydney, and myself from Blue Mountains Botanic Gardens, Mount Tomah, play important roles in the conservation efforts to save the Wollemi Pine and in providing arboricultural advice on growing and maintaining this ancient tree.

Many of our arborists are providing advice on habitat tree management and developing habitat trees in our gardens for endangered bird species such as Gang Gang cockatoos.

Our colleagues across the Tasman in New Zealand are also doing incredible work on Kauri Dieback and managing ancient veteran Rimu trees.

These are just a few examples of the breadth and depth of what botanic gardens arborists are doing for our trees and some of the benefits our trees and tree management teams provide.

Peter Berbee from RBGV collecting Corymbia maculata seed from a disjunct population with rare genetics at Mottle Range in eastern Victoria. Credit: Jim Shugg

Our trees and our arborists are clearly of great value, but just to drive it home, we can quantify some of these benefits in dollars.

BARB is working with BGANZ to look at ways we can quantify some of the economic benefits our trees provide, even just in terms of carbon sequestration and pollution capture. Early ballpark figures using peer reviewed online tools indicate the trees in just one of our member gardens provide hundreds of thousands of dollars of those benefits each year. There has also been some work on determining dollar values of individual trees by arborists at several member gardens. Based on recognised tree valuation methods, it would be reasonable to value just one moderately sized mature tree in one of our collections at tens of thousands of dollars. I’m better at looking after trees than I am at maths, but the value of our trees in BGANZ gardens and the benefits they provide is definitely well into the tens of millions of dollars.

With an asset like that, we hope we see the continued support of our arborists and the resourcing of specialist arboriculture teams for the gardens that don’t have them.

BARB is committed to providing network support to all our member gardens to help with whatever tree management issues they have. For a contact list of BARB arborists, please email me at ian.allan@botanicgardens.nsw.gov.au

THANK YOU TO OUR DIAMOND SPONSORS

Thank you to the Australian National Botanic Gardens, Botanic Gardens of Sydney, Kings Park & Botanic Gardens and the Royal Botanic Gardens Victoria for their very generous support of BGANZ.

This support enables us to focus on key projects that drive significant benefit to botanic gardens and we look forward to servicing and delivering higher benefits to all members thanks to their support.

Botanic news: from home and abroad

Cassandra Nichols, CEO, BGANZ Ltd

Thank you to John Arnott

As many of you will know, John has finally hung up his gardening boots at the RBGV Cranbourne Gardens, where he was Manager Horticulture for 16 years. His career started at Melbourne Zoo in 1980 as an apprentice gardener.

John is a founding member of BGANZ and a well known botanic force of nature. His passion and ongoing commitment to public botanic gardens, plant conservation and BGANZ is truly remarkable.

Thank you, John, for your time, passion and expertise. You have been and will continue to be an incredible asset to BGANZ. We look forward to working with you in future.

To learn more about John’s long career in horticulture, see our Feature Interview with him from 2021, here

New members

BGANZ is delighted to welcome the following new members in 2024:

• Armidale Council (Armidale Bicentennial Arboretum, Dumaresq Dam, Central Park)

• The Friends of Burnley Gardens.

We also have six new individual members. Welcome all!

John in 1992

John in 2022

Grant to support the UniSA Garden Visitor Survey successful

We were very pleased to announce that we have been successful in receiving a grant to proceed with the UniSA visitor survey at the very reduced cost of $1500 per garden. Thank you to everyone who provided letters of support. We are very excited by this opportunity and the data it will provide for the sector.

The offer is open to all BGANZ members so please contact us if you are interested. The more who participate, the greater strength we have in advocating the social well being and tourism value of botanic gardens and arboreta, so we encourage gardens to join if they can.

Please email secretariat@bganz.org.au if you would like to join the survey or need more information about it.

8th Global Botanic Gardens Congress (8GBGC ), Singapore, 6–9 August 2024

I will be attending the Congress and hope to meet many of you there.

If you cannot attend in person, virtual registration is available. An Institutional Rate is available upon request and discounted rates are offered for bulk purchases by institutions. Please contact 8gbgc.sbg@pico.com for more information.

SAVE THE DATE — 8th Botanic Gardens Australia and New Zealand Conference 2025 — Advancing our reach: innovation and leadership in botanic gardens, 3–5 November 2025, Canberra

Hosted by Botanic Gardens Australia and New Zealand, and the Australian National Botanic Gardens.

Share knowledge and experience to advance the role of botanic gardens as globally recognised centres of excellence for plant science, conservation, education, and outreach.

ANBG looks forward to showcasing their beautiful gardens, Australia’s capital city and stunning regional surrounds.

Aug 2024

• Conference website live

Dec 2024

• Early bird registration opens

• Call for abstracts

May 2025

• Abstracts Close

Botanic Gardens Day 2024

I had the pleasure of visiting WAMA’s Grampians/Gariwerd Endemic Botanic Gardens on Botanic Gardens Day, 26 May, for their opening.

What an impressive living collection telling the incredible story of the value of the Grampians to Victoria’s floral biodiversity. More than a third of Victoria’s native species are found in the Grampians, with many of these endemic to the region. Created in 2022, WAMA’s endemic botanic gardens display most of the 70 plant species that only grow within the Grampians region. It’s a vital biodiversity hotspot.

The gardens are an excellent example of what can be created by an individual’s passion and vision, and a strong network of volunteers. Congratulations to the community for bringing this amazing space to life and we look forward to sharing the progress as it grows!

Thank you to all the gardens, from every state and territory in Australia and from both islands in NZ, who participated in this year’s Botanic Gardens Day, either via their social media or with live events. The number of gardens participating was up 20% compared to 2023. Our social media reach was also up by 52% and we had almost 450% more visitors to our website!

Thank you to Dianne Winkworth, a volunteer on our Botanic Gardens Day working group, from the Friends of Melton Botanic Garden, for her fantastic help with getting the word out.

The number of gardens participating was up 20% compared to 2023.

Left: Thank you to Jill Burness (WAMA Board member, ex RBGV Cranbourne Gardens landscape planner and BGANZ Individual member) for giving me an excellent personalised tour. Right: Greg Lewin, WAMA’s Chairman and yours truly.

Dianne hard at work volunteering at Melton Botanic Garden

If you haven’t returned your post event questionnaire, it’s not too late. Just email it to Rebecca at media@bganz.org.au.

We’d love to know what your garden’s social media reach was, so please include it in the questionnaire.

We also had five news articles and five radio stations cover events in NZ, Vic, NSW and the NT. Our old friend Costa must have put a good word in for us as we were even mentioned on the ABC Gardening Australia website! Thank you to Eucalypt Australia and the Ironwood Institute for your help with online promotion as well.

A huge thank you to all the members of our Botanic Gardens Day working groups; John Arnott, Ellie Cheney, Amalia McLaren Brown, Amanda Coleman, Alison Morgan and Helen McHugh, and a special thank you to our webinar production team volunteers Pippa Lucas, from Auckland Botanic Gardens, and James Roche, a science communications student from the ANU on placement at ANBG. Both worked hard behind the scenes organising speakers, making videos and analysing data.

A big thank you to every one of you.

Botanic Gardens Day 2025

Next year is the 10th anniversary of Botanic Gardens Day and we’d like your ideas on how we can celebrate it. If you would like to be on the working group, please send an EOI to Rebecca, at media@bganz.org.au.

James Roche

THE BOTANIC GARDENer: Winter 2024 - Issue 62

Editorial Committee

CONTENTS

Feature

Feature

Pollinating Great Ideas

Notes From the Nursery

Specialist Groups

What’s new?

Editorial insights

Grow as a Leader in Public Horticulture

Nathan Emery: fighting the extinction battle seed-by-seed

Further

Saving threatened species at the Australian Botanic Garden Mount Annan – one ecological community at a time

From the nursery to the field: horticulture informs translocation of Small Purple Pea Swainsona recta

Seed collection from wild populations

Propagation and cultivation techniques

Seed production

Ex situ ‘insurance’ collections

Maintaining genetic differentiation

Cultivation informs planting requirements and post-planting care

Horticultural experimentation informs translocation methods

Combining our expertise for better outcomes

Next steps

Further reading

Joining forces: aligning ex situ and in situ threatened plant conservation programs to support regional priorities

Further reading

Hortis – the plant record platform selected by BGANZ

Perennial management and garden design

A BGANZ Young Member Award 2023 Report

Background

Learnings

Hidden assets

Further reading

The role of botanic gardens in fighting the extinction battle

Further reading

News from BCARM, the BGANZ Collection and Record Management group

THANK YOU TO OUR DIAMOND SPONSORS

Botanic news: from home and abroad

Thank you to John Arnott

New members

Grant to support the UniSA Garden Visitor Survey successful

Botanic Gardens Day 2024

Botanic Gardens Day 2025

Articles inside

News from BARB, the BGANZ Arboriculture Professional Group

What's new? - Botanic news: from home and abroad

News from BCARM, the BGANZ Collection and Record Management group

Notes from the nursery - The role of botanic gardens in fighting the extinction battle

Pollinating great ideas - Hidden assets

Pollinating great ideas - Perennial management and garden design

Feature article - Joining forces: aligning ex situ and in situ threatened plant conservation programs to support regional priorities

Feature article - From the nursery to the field: horticulture informs translocation of Small Purple Pea Swainsona recta

Feature garden - Saving threatened species at the Australian Botanic Garden Mount Annan – one ecological community at a time

Feature interview - Nathan Emery: fighting the extinction battle seed-by-seed

Editorial insights

CONTENTS