Make Your Own Soil Conditioner

Autumn leaves are an asset when converted into leafmould, says Tim Rumball

- Tim Rumball

It can be a bit dispiriting when, each autumn, a blanket of fallen leaves covers your garden lawn, flowerbeds and paths. They smother grass, encourage moulds on plants, and are a haven for slugs and snails, so they have to be moved. However, they are also a huge opportunity. If gathered and stored in a bin or a bag, they’ll break down into a wonderful humus-rich soil conditioner called leafmould that you can use all around the garden.

Leafmould is humus-rich material. It improves the structure of the soil and is easy to make, but it takes quite a long time for the leaves to rot down

How it works

Leaves from deciduous shrubs and trees are broken down into leafmould by fungi. This is different from your normal garden compost, which depends on the action of bacteria and is much faster. Small quantities of leaves can be added to the ordinary compost bin, but the vast piles we get in autumn would upset the compost balance. For this reason, they’re best treated separately.

The best leaves to use for leafmould are small types from the likes of oak, beech, lime and hazel, all of which break down easily. Thicker leaves like sycamore and horse chestnut take longer. There’s an argument that if you mix different types it’s a problem because they rot down at different speeds, but I think this is of little importance – and you’re hardly going to sit and sort out the different leaves, are you, really?

Ways of harvesting

Collect leaves from your own and friends’ gardens. You can rake them up, but if you have a rotary lawnmower with a grass box it’s easier and better to rake them all onto the lawn and run over them with the mower. This shreds the leaves as it collects them, which speeds up decomposition – and is particularly useful for the bigger, tougher leaves.