Keeping it local

We’re used to being encouraged to ‘shop local’, but these days there is just as much of a focus on ‘growing local’. In recent years the importance of retaining the island’s biodiversity has been in the spotlight, with planners now encouraging native planting and restricting the use of non-native plants in developments.

When the Development & Planning Authority is considering planning applications, their effect on the island’s biodiversity is now a key aspect. It means that those planning the landscaping for development schemes have to carefully consider what they are planning to use to ensure that they respect and protect the island’s environment.

Elliot Green is an experienced landscape designer with his firm, Sexton Green Landscapes and has completed projects all over the island. He’s clearly aware of the importance of using native plants within the schemes he develops. But while it’s something he supports, he says there are challenges around it.

“Part of the problem is defining what is native. Sometimes plants we think are native to the UK aren’t native to the whole of the UK and aren’t native to Guernsey. When you look at what is considered native to Guernsey, the list of possible selections for schemes can become very small.”

Elliot, like others in the industry, finds Andrew Lee’s book ‘Native plants for Guernsey wildlife’ a good resource, and says it’s well-used in the Sexton Green office when they are looking to specify trees and hedging.

“It has a key that shows species that are Guernsey native, are probably Guernsey native, and are plausibly Guernsey native, so that gives us a really good starting point. But we do have to look at projects in their entirety to work out what would be the best thing to use. Guernsey is a small island and it is hugely important to protect its environment but from a landscape architecture point of view we are also looking for the best solutions for a site.”

When considering development schemes, local planners like to see as many native trees and native hedging as possible. But, as Elliot points out, it is a fairly short list. There are less than half a dozen native trees, with one of them, ash, unable to be imported or used due to the risk of disease. That leaves oak, elder, hawthorn and grey willow as the options, and Elliot says they’re not always ideal for every area of a site.

“It is a balance between specifying native trees and making sure that the ones you choose are both aesthetically pleasing and able to do the job required. Some trees are not suitable for streets or urban environments. In a car park, for example, you have to think about leaf letting and debris landing on cars. When we can, we will always specify native trees but sometimes the best tree for a job isn’t.”

English Oak

As well as trees, hedging is often an important part of the landscape design. Elliot says while again they try to plant native, that can conflict with what their clients are looking for.

“A native mix might have five different varieties of hedging within it. We tend to use 75% hawthorn and 25% of another variety of native hedging. But sometimes that doesn’t suit the client, who may, for example, want an evergreen hedge. Holly is plausibly native to Guernsey, but it’s very spiky so no good if you’re picking footballs out of it. Again, holly or hawthorn aren’t really suitable for car parks with lots of people walking past them. And you also have to balance out the fact that something like an evergreen holly hedge is both very expensive to buy and slow to grow.”

For Elliot, it’s a constant balance between ensuring his designs protect the island’s natural environment and meet his clients’ expectations and budgets.

“On the bigger developments, we can do things like pack the boundary planting with native varieties and put non-native species elsewhere on the site. And we’re always keen to plant as many trees as possible wherever we are working, as long as we ensure we allow the correct spacing for them to thrive.”

While Elliot is an expert, for amateur gardeners or those less experienced, it can be hard to know what plants would be positive for the island. Luckily, one recent initiative is hoping to help with this. A collaboration between the botany section of La Societe Guernesiaise and GROW Limited, ‘Grow Guernsey Natives’ has been launched to help preserve the island’s native plant species. Hawthorn

The scheme will see native plants grown and sold by the charity, with 20% of profits going to La Societe and 80% to GROW to support their future work. At the moment seven species of rare and naturalised plants can be purchased at GROW – Purple Toadflax, Sheep’s Bit, Oxeye Daisy, Largeflowered Evening Primrose, Hoary Stock, Field Scabious and Deptford Pink. That range is set to increase, with around 20 to 25 different native and naturalised plants eventually planned to be for sale.

Grey willow Elderflower

The hope is that the scheme will help educate the public about the importance of choosing native plants as well as promoting their use in the island. Guernsey has 167 plant species classified as rare in the British Isles and 34 species which are found in fewer than 25 locations – so it is really hoped that this will help protect that biodiversity, while helping an important local charity at the same time.

KNOT A PROBLEM

While many non-native plants exist in Guernsey without having too negative an impact on the local environment, there are some very notable exceptions.

Japanese knotweed (also known

as Donkey’s Rhubarb or Mexican bamboo) is well-known for how quickly it can spread and the damage it can do. Introduced to Britain from the Far East in 1825 as an ornamental plant, it is now the most invasive plant in Britain and Guernsey.

The knotweed spreads rapidly and takes over native plants and flowers, as well as causing structural damage to buildings through its roots and stems. Removing it from a site is both tricky and very timeconsuming.

Sour fig is also classified as an invasive non-native species, and is very quick to spread in the wild. Due to its growth cycle it can change the chemical composition of the soil to give it a competitive advantage over native plants and create a monoculture.

Aerial photographs of the island show that the amount of sour fig on Guernsey increased by 3,839% from 1990 to 2019 so there are comprehensive efforts underway to tackle the problem and help protect and improve the island’s biodiversity.