In an organic garden, we should always try to understand and make use of nature’s cycles. Using fallen leaves to make leaf mould is one way we can help perpetuate nature’s cycles while also working with nature to achieve our own goals. But do you know how to make leaf mould?
Leaves that fall from deciduous trees and shrubs will naturally lie on the soil surface below. There, the varied creatures of the soil ecosystem will set to work, breaking them down and returning their nutrients to the topsoil, where they form a rich humus that will enrich the soil structure and feed the surrounding plants.
As they break down, the fallen leaves will also provide a valuable habitat for a range of invertebrates and other creatures.
It is important to understand that it is not always necessary (or a good idea) to rake and clear away all the leaves that fall in your garden.
Leaves should sometimes simply be left, to allow nature to take its course. Leaving some fallen leaves where they lie can often be beneficial not only for the soil and the plants, but also for local wildlife.
But there will be times when it is a good idea to collect up fallen leaves. For example:
- Too many leaves on a lawn area will exclude light, which can create bare patches or discoloured areas.
- Leaves on a path, driveway or areas of paving can be slippery, and cause a hazard.
- Leaves that fall into or blow into a pond can cause it to silt up and become sludgy and full of rotten vegetation. Rotting vegetation can overload the nutrient balance of the pond. It can, therefore, be a good idea to remove excess leaf fall from the area before they blow into the water.
If you have a lot of leaves to collect up, making leaf mould can be a good idea. And we have the best guide on how to make leaf mould to help you get started
What is Leaf Mould?
Leaf mould is a material made of part-composted or composted leaves after these fall from deciduous trees in the autumn. Leaf mould is akin to the humus found on a forest floor, and the idea is to replicate this material, which is great for plant growth.
What Are The Benefits of Using Leaf Mould?
Leaf mould is one of the best mulches or soil conditioners around and the good news is that anyone can make it. Pretty much all you really need to generate this useful material for your garden are autumn leaves, and time.
As we will discuss later in this article, there are several important ways in which leaf mould can really come in handy in the garden. Making your own leaf mould can save you money and avoid the necessity of importing soil amendments or potting mixes for your garden.
How To Make Leaf Mould
If you’ve decided that you want to give this material a try in your garden, we have a step by step guide on how to make leaf mould to get you on your way.
To make leaf mould, there is a simple process to follow.
You Will Need:
- Autumn leaves.
- A leaf rake or other tools to gather the leaves.
- A leaf bin or receptacle for leaf storage
The first step is to decide where you will store the leaves as they break down, and to create a leaf bin or other storage area.
Next, you just:
- Collect fallen leaves.
- Store the leaves.
- And wait for them to break down.
Collecting Leaves for Leaf Mould
Some leaves are better than others for creating leaf mould.
Oak, beech and hornbeam leaves are best of all. Though all deciduous trees’ leaves will work fine, some thick leaves such as sycamore and horse chestnut will take far longer to break down – shredding them can speed up this process.
It is best not to add evergreen leaves to your general purpose leaf mould pile and pine needles are best kept separate to make a separate soil-enricher or mulch that will be perfect for acid-loving plants.
Do not worry about getting some grass in with your leaves, this will just make your leaf mould richer in nutrients. Do try to avoid spreading weeds into your leaf mould pile as these could potentially become a problem if you do not keep on top of it.
Storing Leaves
It is possible to use black bin bags with holes pricked in them to store your leaves. However, if, like me, you prefer to be more sustainable and avoid using the plastic then you can easily just make a mesh bin or fenced off area in which to store your leaves as they rot down.
Try to make sure that you create a structure that is large enough to accommodate all the fallen leaves that you would like to collect from your property. And make sure that it is in a relatively sheltered position so that the leaves that you gather do not blow away.
Maintaining a Leaf Bin
Allow for plenty of ventilation in the structure so the leaves do not get slimy and air is able to circulate.
It is also best to create some sort of lift-able cover for your leaf pile so it does not become too wet. (Also, in very dry weather, it is best to sprinkle your leaves with a little water to make sure that the decomposition can continue.)
When is Leaf Mould Ready To Use?
Once you’ve followed these steps for how to make leaf mould, it’s a game of waiting. After one year, your leaves will have broken down into a crumbly mulch that can be placed around mature plants in your garden.
Leave them be for another year, however, and your leaves will have completely broken down into a friable soil conditioner that will be perfect for potting up, along with home-made compost, or for adding fertility to your growing areas.
After a year, the leaves that did almost fill our leaf bin will have sunk down and will now fill only around half the structure. I will then take out some of the mulch material for use around plants in the polytunnel, leaving the rest in place.
On the second year, in autumn, I will lift the mesh at the base of the bin and dig under the top layer of partially composted leaves (from the previous year) to retrieve the leaf mould from the bottom of the leaf bin.
Adding a second compartment to your leaf bin could make this process easier, as you could add new leaves to the second area while leaving the leaves in the first one to break down for a second year.
What To Use Leaf Mould For
Leaf mould is one of the best mulches or soil conditioners that you can make. It can be used:
- As a mulch to keep down weeds and reduce moisture evaporation from the soil.
- As a soil improver, to add fertility to your growing areas.
- For use in a potting mix to grow your plants in containers.
Using 1st Year Leaf Mould As Mulch
After you’ve followed these steps for how to make leaf mould, you can actually start using it after the first year. I find that the material that is partially broken down after almost a year or so is very useful as a mulch for use around plants in my polytunnel garden. I may use some as early as the summer after the leaves were collected, primarily to cover the soil around crops and suppress moisture losses.
Of course, this mulch material also enriches the soil and provides slow release fertility for the plants around which it is planted. It can also help to reduce competition from weeds.
Using 2nd Year Leaf Mould as Soil Improver
Once the leaves have broken down more fully, they are wonderful to spread around plants to improve the soil, and can also be used as autumn top-dressing for grassy areas.
If any areas of the garden have performed rather poorly over the summer, a top dressing of leaf mould can be one way to address this issue and ensure that the soil is as healthy as possible for the next plantings.
Using 2nd Year Leaf Mould in Potting Mix for Containers
But perhaps where I find leaf mould most useful is as a compost or potting mix. I use it frequently for seed starting, and alongside homemade compost and loamy soil to create potting mixes suitable and for container growing a range of different plants.
Fallen leaves in the autumn are a useful commodity. Even if you do not have many fallen leaves in your own garden, you may be able to collect some from the gardens of family, friends or neighbours, or even from a public space/ open land.
Making your own leaf mould is a wonderful idea if you want to grow in an eco-friendly and sustainable way. And it can save you money too as you create closed-loop systems in your garden and avoid the need to purchase any materials to maintain your growing efforts.
FAQs
What are the benefits of using leaf mold in gardening?
Leaf mold improves soil structure by enhancing its ability to retain water and nutrients. It also aids in aeration, provides a habitat for beneficial soil organisms, and slowly releases nutrients into the soil, making it an excellent soil amendment for garden beds.
Can leaf mold replace other types of compost?
While leaf mold is rich in nutrients, it mainly excels in improving soil structure and water retention. It can be used in conjunction with other types of compost to provide a balanced nutrient mix for plants.
Is leaf mold acidic, and how does it affect soil pH?
Leaf mold typically has a nearly neutral pH, although the initial material—fallen leaves—can be slightly acidic. Generally, leaf mold does not significantly alter soil pH, making it suitable for a wide range of plants.
Sources:
Christian, E., (2024) 12 Gardening Jobs for October. Rest Less. [online] Available at: https://restless.co.uk/leisure-and-lifestyle/home-garden/gardening-jobs-for-october [accessed 30/9/24]
