When autumn arrives, it is tempting to think the gardening season is winding down. But while there may be fewer flowers to plant and less mowing to do, there’s plenty of Autumn gardening jobs you can do.
Autumn and winter are a great time to improve your soil. Whether you want to improve poor garden soil, increase fertility or simply prepare your borders for spring, autumn and winter give you plenty of time to work on your soil. Adding organic matter, protecting the soil from winter weather and tackling problems such as compacting now can all help create better growing conditions when spring comes around. If you're not sure where to start, our guide to healthier garden soil and better plants covers the basics of soil health, from improving structure and fertility to dealing with common soil problems.
Whether you’re working with heavy clay, dry sandy soil or a tired looking border, a little soil improvement over the colder months can go a long way.
Why is autumn a good time to improve your soil?
Healthy soil is the foundation of a healthy garden. It provides plants with the water, nutrients and support they need, while also creating a home for earth worms, fungi and countless other organisms that help keep the soil healthy.
Autumn is a particularly useful time to work on soil because there's no need to rush. Organic matter added to the soil has months to break down, while rain, worms and natural soil activity gradually help incorporate it. By the time spring arrives, your soil can be in much better shape and ready for new growth.
Improving your garden soil can help to:
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Improve drainage in heavy soils
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Help sandy soils retain moisture
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Improve soil structure
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Increase availability of nutrients
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Encourage healthy root growth
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Support beneficial soil life
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Prepare borders and vegetable beds for spring planting
It’s also a good chance to tackle tired, or compacted areas before the busy spring gardening season begins.
Start by understanding your soil
Before reaching for the compost, manure or mulch, take a look at the soil you already have.
Most garden soils fall broadly into four categories: clay, sandy, loamy and chalky, knowing which type you’re working with can help you decide what it needs.
How to improve clay soil
Clay soil contains lots of fine particles, making it heavy or sticky when wet. It can drain slowly and is particularly prone to compaction and waterlogging.
Adding organic matter such as compost or well-rotted manure can help improve its structure, creating more space for air and water to move through the soil.
Avoid working clay soil when it is very wet, though. Walking on or digging waterlogged clay can cause further compaction and damage its structure.
How to improve sandy soil
Sandy soil tends to be light and free-draining, which can be useful, but it also means that water and nutrients can disappear quickly.
Adding organic matter can help sandy soil hold onto moisture and nutrients for longer, creating a more consistent growing environment for plants.
How to improve loamy soil
Loamu soil is generally well-balanced, with a good combination of drainage, moisture retention and nutrients. It’s often considered an ideal soil for growing a wide range of plants.
Even if you’re lucky enough to have loamy soil, adding organic matter regularly can help maintain its structure and fertility.
How to improve chalky soil
Chalky soil is typically alkaline and free draining. This suits plenty of plants, but acid loving
varieties can struggle if the soil pH isn’t suitable for them.
If you’re unsure what type of soil you have, a simple soil test can help you understand its pH and give you a better idea of what will grow well.
Improve soil with homemade compost
If you make your own compost, autumn is a great time to put it to work.
Compost adds organic matter to the soil, helping improve its structure while providing nutrients for plants. It can also help sandy soil retain more moisture and improve the structure of heavier clay soils.
Spread a layer over flower borders, vegetable beds and other areas that will be planted in spring. It can also be used around established plants, keeping the compost away from the base of stems.
You don't necessarily need to dig it deeply into an established border. A layer of around 5cm of mature compost spread evenly over the surface can be enough to get things started.
Over time, worms and other soil organisms will help incorporate the organic matter into the soil.
And if you’re making your own compost, autumn is a good time to add fallen leaves, spent plants and other suitable garden material to your compost heap or compost bin.
For more information on how to make your own compost see our complete guide on making compost as home.
Use bought compost and soil improvers
Homemade compost is fantastic, but most gardens won't have enough of it to improve every border and vegetable bed.
That’s where bought compost and soil improvers can come in handy.
A good quality compost can be particularly useful when:
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Preparing a new border
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Improving tired soil
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Filling or refreshing raised beds
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Growing in containers
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Preparing vegetable beds
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Supplementing homemade compost
If you’re working on a larger area, bulk compost or soil improvers can also be a practical option.
The key is to choose a suitable product for what you’re trying to grow rather than simply adding as much compost as possible. Different plants and growing situations have different requirements.
Add well rotted manure
Well rotted manure is another useful source of organic matter and nutrients.
It can help improve soil structure and is particularly useful in vegetable beds, borders and other areas where plants benefit from fertile soil.
But there’s an important distinction between well-rotted manure and fresh manure.
Fresh manure can be too strong for plants and may contain high levels of nutrients that can damage roots. It can also contain weed seeds so it shouldn’t simply be spread around established plants.
Well-rotted manure should be dark, crumbly and well decomposed rather than fresh and fibrous.
It’s also worth remembering that not every plant wants rich soil. Some plants naturally prefer poorer, well drained conditions, so don't assume that every part of the garden needs a thick layer of manure.
Make the most of fallen leaves
If there’s one thing autumn gives gardeners plenty of, it’s leaves.
Instead of seeing them all as garden waste, collect them and turn them into leaf mould.
Leaf mould is made by allowing fallen leaves to decompose over time. Unlike traditional compost, the process is largely driven by fungi rather than the head generated by a typical compost heap.
Making it is surprisingly simple. Collect your leaves, keep them damp and place them somewhere they can gradually break down, such as a leaf mould bin, bag or wire enclosure.
Different leaves take different amounts of time to decompose. Thin, soft leaves tend to break down more quickly, while thicker, tougher leaves can take longer.
Once mature, lead mould makes an excellent soil conditioner. It can improve soil structure and moisture retention, making it particularly useful for improving tired or sandy soils.
If you want to make your own autumn is the perfect time to start.
For more information on making leaf mould see our complete guide on how to make leaf mould.
Finish with a layer of mulch
Once you’ve added organic matter, give your soil some protection for the months ahead with a layer of mulch.
Mulching means covering the surface of the soil with a layer of material. As well as helping suppress weeds, mulch can reduce moisture loss and protect the soil surface from heavy rain and winter weather.
Organic mulches can also gradually break down and add further organic matter to the soil.
Suitable options include:
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Compost
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Well rotted manure
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Leaf mould
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Bark chippings
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Suitable wood-based mulches
Spread mulch evenly across the soil, but avoid piling it directly against plant stems or tree trunks. Leaving a small gap around the base helps prevent excess moisture from sitting against the plant.
You don’t always need to dig everything over
Improving soil doesn’t necessarily mean getting the spade out and turning over the entire garden.
For established borders, simply spreading organic matter over the surface can be enough. Earthworms and other soil organisms will gradually help incorporate it into the soil, while leaving the existing soil structure relatively undisturbed.
This can be a particularly useful approach if your soil is already in reasonable condition.
Digging still has its place, particularly when creating a new bed or dealing with specific soil problems, but there’s no need to disturb established soil simply for the sake of it.
Sometimes, less digging and more mulching is all your soil needs.
Protect your soil over winter
Once you’ve improved your soil, the final step is to protect it.
Try not to leave large areas of soil completely bare where you can avoid it. A layer of mulch can help protect the surface, while green manures or cover crops can be useful for empty vegetable beds.
It is also important to avoid working soil when it’s waterlogged or frozen.
This is particularly important with clay soil. Walking across wet beds or digging when the soil is saturated can squeeze out air spaces and cause compaction.
If the soil sticks heavily to your boots or tools, it’s usually a good sign to leave it alone and wait for a drier day.
What should you not add to your soil?
When it comes to improving soil, more isn’t always better.
Avoid adding:
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Fresh manure: it can be too strong for plants and may damage roots.
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Diseased plant material: don’t add diseased plants to homemade compost where the composting process may not reliably destroy pathogens.
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Too much of one amendment: soil needs balance, and excessive additions can create new problems.
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Poor quality compost: choose a reputable compost or soil improver suitable for its intended use.
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Large quantities of uncomposted woody material: fresh woody material can temporarily tie up nitrogen as it breaks down
The aim isn’t to completely transform your soil overnight. It’s about gradually improving its structure, fertility and ability to support healthy plant growth.
You don't need to spend your whole winter digging, feeding and fussing over your soil.
For most gardens, a simple combination of adding organic matter, protecting the soil with mulch and avoiding unnecessary compaction can make a real difference.
Then, when the first signs of spring arrive, you’ll have a healthier foundation ready for the growing season ahead.
Frequently asked questions about improving garden soil
How can I improve my garden soil naturally?
The best way to naturally improve garden soil is to add plenty of organic matter. Well rotted garden compost, homemade compost, leaf mould and well rotted manure can all help to improve soil structure while adding nutrients. Spread a layer over the soil and gently work it into the surface, or leave it on top for worms and other soil organisms to naturally incorporate.
It is also worth avoiding unnecessary digging, keeping the soil covered with plants or mulch where possible and growing a variety of plants. Over time, these simple steps can improve soil structure, drainage and moisture retention naturally.
What should I add to the soil in the autumn?
Autumn is a great time to add organic matter to your soil before the main growing season begins. Well rotted manure, compost and leaf mould can all be used to improve soil structure and add organic matter.
A layer of mulch can also help protect the soil over the colder months, while fallen leaves can be collected to create leaf mould. The right material depends on your soil type and what you’re planning to grow, but adding organic matter regularly is one of the simplest ways to build healthier garden soil.
Is autumn a good time to add compost to my soil?
Yes. Autumn is a fantastic time to add compost to your soil. Adding an extra layer of compost in autumn gives it plenty of time to settle and break down over the winter months, ready for spring planting.
Spread compost over bare soil and gently incorporate it into the surface or use it as mulch around already established plants. You do not need to dig deeply into the soil, leaving organic matter near the surface allows worms and natural soil activity to help work it down.
How do I improve clay soil?
Clay soil can be heavy, compacted and slow to drain, but adding organic matter regularly can make a noticeable difference. Add garden compost, well rotted manure or leaf mould to help improve the soil structure, drainage and ability to hold air.
How do I improve sandy soil?
Sandy soil tends to drain quickly and can struggle to retain moisture and nutrients. Adding plenty of organic matter such as compost, well rotted manure or leaf mould can help improve its ability to hold water and nutrients around plants.
Apply organic matter regularly rather than relying on one single application. A layer of mulch can also help reduce moisture loss from the surface, particularly during drier periods. Over time these additions can help sandy soil become more fertile and better able to support plant growth.
Should I mulch my garden over winter?
Yes, mulching your garden over winter can help protect and improve the soil. A layer of organic mulch such as garden compost, well rotted manure or leaf mould, helps protect the soil surface from heavy rain and erosion while reducing moisture loss and providing organic matter.
Apply mulch to bare soil and around established plants, keeping it slightly away from plant stems and the crowns of plants. Autumn is a particularly useful time to mulch because the material can gradually break down over winter, helping prepare the soil for the growing season.