Every autumn, gardens are filled with fallen leaves. For many gardeners, that means hours spent raking, bagging and clearing them away. But before you send your leaves to the green waste bin, there’s another option: turn them into leaf mould.
Leaf mould is one of the simplest ways to make a useful soil conditioner at home, using something you already have in your garden. It costs virtually nothing, takes very little effort and can help improve your soil for years to come.
Unlike traditional compost, leaf mould is made almost entirely from fallen leaves and breaks down primarily through fungal activity. The result is a dark, crumbly material that can be used as a soil improver, mulch or ingredient in homemade growing mixes.
So, if you’re looking for a more sustainable way to garden this autumn, don't think of fallen leaves as waste. Think of them as next year's garden gold.
What is leaf mould?
Leaf mould is a dark crumbly soil conditioner made from decomposed fallen leaves.
Rather than breaking down quickly like a traditional compost heap, leaves gradually decompose through the action of fungi and other microorganisms. Over time, they turn into a soft, earthy material that can be added back to your garden.
Leaf mould is different from homemade compost. Compost usually contains a mixture of materials, including grass clippings, vegetable peelings, garden waste and other organic matter. Leaf mould, meanwhile, is primarily made from fallen leaves.
If you’re interested in making your own compost as well, our step by step composting guide for beginners explains how to get started and what materials to add to a traditional compost bin.
Why make leaf mould?
There are plenty of reasons to save your autumn leaves rather than throwing them away.
It’s completely free
Once you’ve got the leaves, you don’t need to buy anything complicated to get started.
It improves soil structure
Adding organic matter can help create healthier, more workable soil.
It helps retain moisture
Leaf mould can help soil hold onto moisture while still allowing excess water to drain away.
It can improve different soil types
Whether your garden has heavy clay soil or light, sandy soil, adding organic matter can help improve its structure.
It’s useful as a mulch
A layer of leaf mould can be spread around trees, shrubs and perennial plants to help protect and condition the soil.
It makes use of garden waste
Instead of removing bags of fallen leaves from your garden, you can turn them into something useful.
For gardeners trying to adopt more sustainable habits, it is a particularly simple way to work with what your garden naturally produces.
And that’s exactly what makes autumn such an important gardening season, it’s a season for preparing the garden now so it can thrive when spring arrives.
When is the best time to collect leaves?
Autumn is the best time to start making leaf mould, simply because this is when deciduous trees naturally shed their leaves.
You don't have to wait until every leaf has fallen, collect leaves throughout autumn and gradually add them to your leaf mould pile or container.
In fact, slightly damp leaves are ideal. Wet leaves generally break down more quickly than very dry ones, so there’s no need to wait for them to dry out before collecting them.
However, it is best to avoid letting thick layers of wet leaves build up on your lawn. A heavy covering can block light and trap moisture, potentially encouraging moss and other lawn problems.
If you’re giving your lawn its tidy up at the same time, take a look at our guide on how to care for your lawn in autumn for more advice on scarifying, mowing, feeding and preparing your grass for winter.
Which leaves are best for leaf mould?
Most deciduous tree leaves are suitable for making leaf mould.
Some particularly good choices include:
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Oak leaves
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Beech leaves
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Birch leaves
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Hazel leaves
Thicker leaves, such as sycamore and horse chestnut, can also be used but may take longer to break down. Shredding them can speed up the process.
Evergreen leaves and conifer needles tend to decompose more slowly, so they aren’t usually the best choice if you want your leaf mould relatively quickly.
It’s also best to avoid collecting large quantities of leaves from plants showing signs of disease. While leaf mould can be a useful way to recycle healthy fallen leaves, diseased plant material is better disposed of appropriately rather than added to your homemade leaf mould.
How to make leaf mould
The good news is that making leaf mould is incredibly simple. You don’t need to create the carefully balanced mixture of brown and green materials required from traditional compost.
Here’s how to make leaf mould at home.
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Collect fallen leaves
Start by collecting fallen leaves from your lawn, border and garden.
A garden rake makes light work of gathering leaves from larger areas, while a leaf blower or garden vacuum can also be useful for bigger gardens.
If you’re clearing leaves from your lawn, try to collect them regularly rather than allowing a thick layer to build up.
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Remove rubbish and large twigs
Pick out any rubbish, stones and larger sticks before adding your leaves to the pile.
You don’t need to remove every tiny piece of twig, but keeping the material relatively leaf heavy will help create a more consistent finished product.
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Shred larger leaves
This step is essential, but shredding leaves can significantly speed up decomposition.
You can run leaves over with a lawn mower or use a leaf shredder before adding them to your pile.
Smaller pieces have more surface area exposed to moisture and fungal activity, meaning they can break down more quickly than whole leaves.
It’s another reason why a mower can be a surprisingly useful tool during an autumn garden clear-up.
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Create a leaf mould pile or container
You can make leaf mould in several different ways.
A simple leaf mould cage made from chicken wire is an inexpensive option for larger gardens. Alternatively, you can use a large breathable garden bag or purpose built leaf mould container.
The important thing is to avoid completely airtight containers. Airflow is important for decomposition, so the leaves need some ventilation.
A dedicated area tucked away in a corner of the garden can work particularly well.
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Keep the leaves damp
Leaf mould shouldn’t be allowed to become completely dry.
If the weather is particularly dry, you can give the pile a little water. You’re aiming for leaves that air consistently moist but not waterlogged.
Once autumn rain arrives, you may find that nature does most of the work for you.
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Leave the leaves to decompose
And now comes the easiest part: wait
Unlike traditional composting, leaf mould doesn’t require a lot of maintenance.
You can turn or mix the leaves occasionally to encourage more even decomposition, but this isn’t essential.
If you’ve shredded the leaves and kept them damp, you can largely leave them to do their thing.
Keep your leaf mould pile or bin somewhere shaded and sheltered, such as behind a shed, under trees or in a quiet corner of the garden. A little shelter will help prevent the leaves from drying out, while keeping them off the ground in a wire bin, compost bag or simple leaf mould container will help keep everything contained.
How long does leaf mould take to make?
One of the most common questions gardeners have is “how long does leaf mould take to make?”
The answer depends on the type of leaves you’re using, how finely they’ve been shredded and the conditions they’re kept in.
Young leaf mould can take around 6-12 months to develop. However, if you want dark, fine and crumbly material associated with mature leaf mould, expect to wait around 1-2 years.
The good news is that you don’t have to wait for the entire pile to mature before using it. Younger leaf mould can still be useful as a mulch, while finer, well rotted leaf mould is better suited to applications such as homemade potting mixes.
The smaller the leaves and the more consistently moist they are, the quicker they’ll break down.
Where should you make leaf mould?
You don’t need a prime spot in the garden for your leaf mould pile.
A shady or sheltered corner is ideal, particularly somewhere that doesn’t dry out too quickly.
You could create a simple wire cage, use breathable bags or choose a dedicated leaf mould container.
The main things to remember are:
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Keep the leaves damp
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Allow some airflow
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Choose a practical location
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Make a reasonably large pile where possible
A larger volume of leaves is better at retaining moisture than a very small pile, which can dry out quickly.
How to speed up leaf mould
Want your leaf mold to break down as quickly as possible?
There are a few simple things you can do:
Shred your leaves
Smaller pieces decompose faster
Keep them moist
Don't allow the pile to completely dry out.
Mix different types of leaves
A mixture can create a more varied texture throughout the pile
Build a decent sized pile
Larger quantities are better at retaining moisture.
And remember: leaf mould is supposed to be a slow process. There’s no need to constantly turn or interfere with it.
How to use leaf mould in your garden
Once your leaf mould is ready, there are plenty of ways to use it.
Use leaf mould as mulch
Spread a layer around trees, shrubs and perennial plants
Mulching can help protect the soil, retain moisture and gradually add organic matter as the material continues to break.
If you’re new to mulching, our beginner’s guide to mulch and its benefits explains more about why mulch is useful and how to apply it.
Mix it into garden borders
Leaf mould can be incorporated into borders to help improve soil structure and add organic matter.
This is particularly useful if your soil is heavy and clay-like or very light and sandy.
Add it to raised beds
Leaf mould can also be incorporated into raised beds as part of a wider soil improvement approach.
If you’re creating or refreshing a raised bed this autumn, our guide on how to fill raised beds covers everything from choosing your materials to creating a healthy growing environment.
Use it in homemade potting mixes
Fine, mature leaf mould can be incorporated into homemade growing mixes.
It’s particularly useful when you want to add organic matter and improve the texture of a growing medium.
For plants with more specific growing requirements, it’s still important to choose the appropriate compost. Our compost buying guide explains the different types of compost and what they’re best suited to.
Leaf mould vs compost: what’s the difference?
Although leaf mould and compost are both made by recycling organic material, they’re not quite the same thing.
Compost contains a broader range of organic materials and is generally richer in nutrients. It’s particularly useful for adding fertility to soil and feeding plants
Leaf mould, on the other hand, is primarily decomposed leaves. Its main benefits are around soil structure, moisture retention and adding organic matter.
That means leaf mould isn’t necessarily a replacement for compost. Both have a useful role to play in a healthy productive garden.
Common leaf mould mistakes to avoid
Making leaf mould is simple, but there are a few mistakes worth avoiding.
Letting leaves dry out completely
Dry leaves can take much longer to decompose. Keep your pile consistently moist where possible.
Using an airtight container
Don’t seal your leaves into a completely airtight container. Good airflow helps the decomposition process. If you’re making leaf mould in a rubbish bag, simply add some holes before letting it work its magic!
Expecting instant results
Leaf mould is a slow process. Give it time, particularly if you’re aiming for fine, mature leaf mould.
Adding food scraps
Food waste belongs in your food bin, not your leaf mould pile. Leaf mould should be primarily made from fallen leaves.
If you’re keen to recycle more of your kitchen and garden waste, our step-by-step composting guide is a good place to start.
Using diseased leaves
Avoid adding large quantities of leaves from plants affected by disease.
Leaf mould FAQs
Can you make leaf mould from any leaves?
Most deciduous leaves can be used to make leaf mould, including oak, beech, birch and hazel. Thicker leaves such as sycamore and horse chestnut can take longer to decompose, while evergreen leaves and conifer needles generally break down more slowly.
How long does leaf mould take to make?
Young leaf mould can take around 6 to 12 months, while mature, dark and crumply leaf mould can take 1 to 2 years. Shredding leaves and keeping them consistently moist can speed up the process.
Does leaf mould need to be turned?
No. Unlike traditional compost, leaf mould doesn’t need regular turning. You can mix it occasionally to encourage decomposition, but it’s not essential.
Can you put leaf mould in the compost?
Yes, fallen leaves can also be added to a traditional compost heap as a source of brown, carbon rich material. However, keeping leaves separate allows you to produce leaf mould specifically for improving soil structure and moisture retention.
Is leaf mould better than compost?
Neither is necessarily better, they just have different uses. Compost is generally richer in nutrients and is useful for feeding soil and plants, while leaf mould is particularly valuable for improving soil structure, moisture retention and organic matter.
Can you make leaf mould in a bag?
Yes. large breathable bags such as jute bags can be used to make leaf mould, provided they allow some airflow and the leaves are kept moist. Avoid completely sealed containers.
Fallen leaves don’t have to be something you simply rake up and throw away.
This autumn, collect them, shred them, keep them damp and let nature take its course. These leaves can become a valuable soil conditioner that helps your garden retain moisture, improves oil structure and that autumn is the new spring.