Autumn Winter
Nature-friendly Gardening Guide
Contents 2 Introduction 4 Why autumn is the best time to plant 6 How to plant a tree 8 Keeping your tree healthy 10 How to prepare your garden for winter 12 The benefits of no-dig 14 Together we can save our bees
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Hello gardeners! Welcome to our Autumn Nature-Friendly Gardening Guide. My name is Ben, and I’m the Head of Horticulture for the Soil Association, the charity that joins forces with nature for a better future. We’ve put together this guide to help gardeners like you support wildlife in your own outdoor space. Whether you have access to a window box, garden or allotment, small changes add up and can make a big difference.
There are also some top tips for how to help wildlife over the winter, from leaving seed heads for songbirds and growing cover crops to protect the soil, to creating much needed habitats for insects.
Did you know that around 87% of UK households have a garden? That’s over 10 million acres! So, making your garden more nature-friendly can have a huge impact on supporting wildlife.
If you have any of your own ideas or tips for creating a nature-friendly haven – please let us know. You can get in touch via Facebook, Instagram or Twitter @soilassociation.
In this guide, we’ll look at what why autumn is a good time to plant and what to plant. I’ll share my experience on how to plant a tree, as well as how to keep it healthy once it’s in the ground.
Happy gardening! Ben Raskin Head of Horticulture
Are you looking for more ways to get involved in the Soil community? We’ve created The Soil Hub, a community Facebook group for you to share and learn all about growing, gardening, cooking and so much more, in a way that’s good for the planet, nature and our health.
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Why autumn is the best time to plant and what to plant While spring is the season of seed sowing, autumn traditionally has been the time for planting in the garden. Why is this? The most important reason is that most plants go dormant during winter. This is their defence mechanism, a way of getting through a season with cold temperatures and low light. Whether they just lose leaves like deciduous trees or die right back down and hibernate underground as herbaceous perennials, these plants shut or slow down their metabolisms and wait for the triggers of longer days or warmer temperatures before shooting back to life in the spring.
By planting in the autumn or winter when the plants are less actively growing, we are less likely to damage them. Since the soil was often frozen over much of the winter, gardeners tried to get the plants into the ground before it became impossible to hack through the icy loam. Even this is slightly misleading though since in many cases the roots can continue to develop and grow even if the top of the tree is not in leaf. A tree planted in November would send out some initial roots, making it ready to get going as soon as the spring arrived. If you wait until spring to plant, they may survive but their roots will be less developed, and they will require more nurturing. My experience with tree planting has shown that if we get trees in the ground by the end of January they mostly survive even in a dry spring and summer. Those planted in or after late February often die, though a good mulch will reduce this risk.
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What to plant in autumn? If you are looking for edible crops then now is the time to be getting the following in ground. Asparagus, rhubarb, artichokes and other perennial vegetables, onion and shallot sets, and even some seeds like broad beans, or winter brassica under plastic. Divide chive clumps, or plant other herbs. Bare rooted trees have to be planted when dormant or you will damage their roots, however even pot grown trees will do better planted in autumn. Green manures for soil protection and health can also be sown in autumn, particularly those of the brassica family and rye grass which both germinate and grow in lower temperatures. What is different due to climate change? In the UK we would historically have had a few months of cold weather, with many days or even weeks of below zero temperatures. Trees would typically lose their leaves sometime around late October and start to sprout again in March. Climate change means we often now do not get any days of frost through the winter months in some parts of the country.
What does this mean for our garden planting plans? On the plus side many plants will keep growing all winter, even if they don’t show it their roots may continue to be active in the warmer soil. It also takes the pressure of that autumn planting since we are able to get onto the soil throughout the winter. There are of course some down sides too. Trees are losing their leaves later and coming into leaf earlier, so our planting window is shorter. Many species of plants like rhubarb and strawberries need a period of cold to stimulate stem or fruit growth for the following season. What does this mean for you and your autumn planting? The good news is that you can probably ignore quite a lot of the advice in old gardening books about planting time. Leave your dahlias in the ground overwinter, there will also be a wider range of plants that will survive in our climate, try looking to Mediterranean natives for inspiration.
How to plant a tree At a time when trees could be helping to save the planet, planting a tree can be an emotional and even a political act. It’s even more vital that the tree not only survives but grows well and quickly. Let’s look at how to give your tree the best start in life so that it is still standing even when your children and grandchildren are long gone from this earth. Digging a hole As a rule, dig a hole just a bit bigger, but no deeper than the roots of the tree you are planting.
Preparing the roots
Bare root trees - these will have little or no soil on the roots. For many species you can prune the roots back before planting. Though this seems drastic, most of the small roots will already have been killed when the tree was lifted, and cutting back will encourage new growth once the tree is in the ground. It makes planting much quicker and easier and has no ill effect on growth. Pot grown trees – often the roots will have started to grow around the inside of the pot, this is called being “pot bound”. With no action pre-planting the tree roots are likely to continue to grow around in a circle in the hole after planting, meaning the tree will never thrive. In mild cases simply take a sharp knife and cut through the thin roots around the edge. This will encourage fresh new roots that should grow outwards. Where there are roots of pencil thickness or more growing around the edge, use secateurs to cut through the root and tease them out of the compost a bit. 6
Planting
Bare root trees – check the hole depth is right, by laying a stick across the top of the hole and making sure the stick lines up with the right part of the tree. Holding the tree firmly with one hand half fill the hold with soil, give the tree a gentle shake to allow the soil to get in between the roots. Firm softly with your feet, then fill the rest of the hole with soil, shake again and then tread more heavily to ensure the tree is properly in the ground. If you have small children, get them to jump up and down around the tree, otherwise use your heel to stamp the soil into place. Pot grown trees are easier, just pop them in the hole, ensuring the top of the root ball lines up with the soil surface, then fill the soil around and firm in as above. The best thing you can do for a sustainable future is to support the Soil Association. Click here to find out more
Compost in the hole or not? Historically it was recommended to add compost into the planting hole. However, I believe this creates a lovely rich planting hole that tree roots are reluctant to leave and that it is better to mulch on top of the tree.
Staking For very tiny saplings, staking may not be necessary as the blowing wind stimulates them to grow strong roots to hold them in place. However for anything over 60cm (2 ft) tall I would recommend a stake, and for bigger trees a strong one is essential.
Watering In a dry year, it is essential to water. It helps to settle the soil amongst the roots ensuring good root/soil contact. The crucial period is in the first spring as the new and still shallow roots grow and look for water. In dry soils this is particularly important. Water perhaps once a week with a really good soak.
Mulching Competition from weeds will have a negative impact on how well and quickly your tree grows. Using a good mulch will increase the water available in the soil by about 25% and can be the difference between death or survival. I recommend a wood chip mulch, of at least 10cm thick. Make sure that it does not touch the trunk of the tree as that can cause a damp area that encourages rotting and disease.
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Keeping your tree healthy You don’t want to waste all the effort spent producing a beautiful and strong tree by neglecting it once it’s in the ground. 8
Good planting with adequate mulching and watering is an essential first step, but a small effort as the tree grows pays dividends once the tree is established. Checking tree ties Allowing a tree to outgrow its tie is a major cause of death in urban tree planting. As the trunk gets bigger it puts pressure on the tie and eventually if nothing is done the tie will dig into the bark and cut off the supply of nutrients and water. Using an elastic material for the tie such as rubber allows for some expansion, but eventually the tree will still outgrow the tie. Check at least once a year in early spring. If the tree still needs support, either loosen the tie or replace it with a bigger one. Eventually the tree no longer needs staking and you can cut the tie off and potentially remove the stake.
Watering Most trees in most years shouldn’t need water beyond the establishment year, and indeed giving too much can be detrimental, encouraging surface rooting which makes the tree more vulnerable to drying out. However in some circumstances you will need to. Trees in pots need regular water, at least once a day in really hot weather. Fruit trees grown on dwarfing rootstocks in soil may also need a drink in long dry spells as their roots don’t have the power to dig deep to find water. Generous infrequent watering is better than a little every day.
Pruning Not all trees need pruning, but it can help to achieve the shape or purpose you want. In many cases some formative pruning in the first couple of years may be enough to give desired length of main stem or encourage branching at a particular point. If you are planning to train a tree against a wall or fence, then this will require ongoing pruning. Pruning fruit trees allows you to get better quality fruit, by allowing more light and air movement through the tree. Annual pruning can also help to balance new and older growth, the key to combating the tendency many trees have towards bienniality, where trees fruit very heavily one year and then give almost nothing the following one.
Weed Con t
Top Tip:
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A really go od mulch when plan ting will re duce the need t o do muc h subsequen t weeding .
How to prepare your garden for winter in a nature-friendly way Garden-grown bird food
Insect habitat
Winter is a hard time for birds with short days and cold nights. They need to take on a good deal of food in a short space of time in order to have energy to survive. One of their favourite food sources, insects, will be hibernating often beyond a barrier of hardened soil, ice or maybe even snow. Packet bought bird food is often used to bridge the gap, but it can be so much more rewarding to grow your own.
Mulching can provide a much needed habitat for insects. Hollow stems and leaf piles can be good hibernation sites for insects such as ladybirds, lace wings and ground beetles. Spiders can also feed on pest insects so leave their eggs undisturbed under rocks and plant debris. Plant stems left to stand and even seed pods can provide much needed shelter, so again resist the urge to clear all ‘finished’ plants away. Even hollow bamboo canes can make useful homes for earwigs which usefully feed on fruit tree pests.
Try sunflowers and globe thistles. Whether you grow these simply for their beautiful flowers or to attract bees, the resulting seed heads will be of great interest to songbirds such as finches. Either leave the plants to mature in situ or bundle cut seed heads together and hang around the garden. Top tip: Crab apples can be a winter gem for birds providing food throughout the winter. The constant freezing and thawing of their fruit softens them, making them particularly easy to eat.
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Top Tip If your garden is running short on naturally occurring shelters, try bundling hollow sticks together a tuck them away under hedges. You could go further and introduce log piles which will bring in the usual suspects but also wildlife further up the food chain such as slow worms, newts and toads.
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In the Sp Top Tip ring :
Let som e phace lia flower t o entice some early po llinators in.
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Cover crops
There is a temptation for gardens to be ‘neatened up’ in the winter ready for spring. This can be problematic. The soil will be feeding off decaying roots and their associated fungal networks so it’s highly beneficial to leave these undisturbed by not turning soil over or pulling roots up. Instead, try cutting plants off at their base. Some plants – and dare we say weeds – can even be left over winter providing ground cover whilst improving drainage.
Cover crops and green manures are an excellent way to look after your soil over winter. Classic options are phacelia and clover which when established in the autumn will provide some green in your garden. These are incorporated back into the soil in spring, increasing soil structure and soil organic matter levels. Expert nitrogen fixers such as hairy vetch and winter peas will gift your soil extra nitrogen ready for next year’s hungry crops.
Top tip: Try not to leave beds bare – you can apply a generous layer of mulch such as woodchip, straw or compost. If using compost, cover with a sack or old compost bag so that the nutrients don’t get washed away, and be sure to uncover when things warm up again in the spring.
Cover crops are as much about what you can’t see. Winter grains can develop huge root systems, great for breaking up stubborn soils and improving water drainage and retention.
The benefits of no-dig Many of you will have heard of no-dig gardening, a method that has gained popularity in recent years and has a lot to offer for soil health and those that depend on it. It’s an organic way of growing plants, and the principle is simple; leave the ground as undisturbed as possible and you’ll end up with less pests, heathier plants and a healthy vibrant soil community.
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Why is it beneficial?
Getting started
Rather than digging the soil to remove weeds, the no-dig method promotes adding garden compost or manure to the surface of the soil. This emulates the natural processes in an ecosystem, as leaves fall to the ground, break down and incorporate into the soil.
If you’d like to convert your lawn into a veg patch then Charles Dowding, a no-dig expert, suggests starting by covering grass with cardboard then adding a thick layer of compost. Use brown sheets of cardboard with minimal ink and remove metal clips and tape. Plant into the top of your compost and mulch around your plants. Over time the soil will become a haven for worms which will help to loosen the soil and keep it aerated. And, yields of vegetables tend to be bigger when grown in no-dig soils!
By doing this, the structure of the soil is also maintained, leaving worms and other soil-dwelling organisms undisturbed and the ecosystem intact. What’s more, it’s a great option for gardeners who don’t have time to dig over beds and borders - let the soil work its magic!
How – doesn’t it take ages? In fact, the opposite is true. Once setup, a no-dig system can be incredibly time efficient. This is because in the long run you will need to spend much less time digging and weeding. No-dig works on the principle that healthy, covered soils are less weedy because weeds are most present in soil that needs healing.
What are mycorrhizae and how to look after them? You may sometimes see white strands within the soil. These are likely to be mycorrhizal fungi which are safe and beneficial. Most plant roots team up with fungal networks working in partnership – the fungi feed off sugars from the roots whilst the plant uses the expansive fungal network to receive nutrients and water beyond its own catchment. These delicate networks are doomed to die if the soil is turned, particularly as the fungi can’t tolerate exposure to the air.
Together we can save our bees 14
35% of UK bee species face extinction. And if we allow bee numbers to continue to decline our wildlife, flowers, plants and even the food we eat will be devastated. But if you join the Soil Association today, together, we can turn this around. We can plant trees to provide bees with the food and habitat they need to thrive; support farmers to grow their crops without pesticides; and lobby the government so that they don’t reverse a recent ban on bee-killing pesticides.
And as a member, you’ll join a community of thousands who are passionate about protecting the future of our pollinators. You’ll be supporting us all in restoring nature, health, and a safe climate from the ground up.
Find out more: soilassociation.org/save-our-bees
Get in touch Soil Association Spear House 51 Victoria Street Bristol BS1 6AD
0300 330 0100 soilassociation.org @soilassociation
Registered Charity No. 206862 in England and Wales. Registered Charity No. SC039168 in Scotland.