Seasonal Autumn ForestBreaking down
Once a leaf lands, a whole community gets to work on it. Fungi and bacteria start digesting the soft tissue. Earthworms, millipedes, woodlice, springtails and many other small animals shred and eat leaves, speeding up the process. Tough leaves, like oak and beech, take longer to break down than soft ones, like ash or birch.
Feeding the soil
As leaves decompose, the nutrients the tree didn't recover in autumn are returned to the soil, where roots can take them up again. What's left becomes humus, dark organic matter that helps soil hold water and air. In a healthy forest, this cycle repeats every year.
A winter shelter
The leaf layer works like a blanket. It insulates the soil from freezing, keeps it moist, and protects it from heavy rain. Many insects, spiders and other small creatures spend the winter in leaf litter, as do some butterflies and moths at various life stages. Those insects in turn feed birds, amphibians and small mammals.
What this means for your garden
- Leave some leaves. A layer under shrubs and around perennials protects roots and gives wildlife a place to overwinter.
- Mow them. A thin layer of leaves on a lawn can be chopped with a mower and left to break down.
- Make leaf mold. Pile leaves in a wire bin or a bag with holes, keep them moist, and wait. In one to two years they become a crumbly soil improver.
- Compost them. Leaves are a good "brown" ingredient to mix with kitchen scraps and grass clippings.
Where to clear leaves
Thick mats of wet leaves can smother lawn grass, and leaves on paths, steps and driveways are slippery. Keep drains and gutters clear, too, to avoid blockages.
In parks and forests
Leave the forest floor as it is. Collecting a few fallen leaves for a craft is fine where allowed, but raking or removing leaf litter disturbs the soil and the creatures living in it.
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