The Wildlife Benefits of Autumn Leaves
When doing a quick (or maybe not so quick; I like to make sure I'm fully informed) spot of research for this article, I came across a blog from Pumpkin Beth (very seasonal) which extols the virtues of fallen autumn leaves. As she poetically puts it on her blog:
"The loud noise that garden vacuums, leaf blowers, and these types of machines generate echoes through the landscape, drowning out all other sound. These gadgets are so intense that their reverberating volume resonates through the local area, overcoming birdsong; replacing the sound of life and joy, with that of misery and oppression"
A bit dramatic maybe, but she’s got a point. Blowing leaves around just to make everything look ‘tidier’ is often a short-sighted and human-centred activity that disrupts and upends natural winter habitats which are essential to all kinds of wildlife.
Away from human interference, leaves play a vital role in the natural life cycle. As they slowly break down they are absorbed by the soil and nourish the next season’s growth. Whether you've gathered your leaves into a DIY cage or simply swept them into piles around the borders of your garden, they will serve as an excellent wildlife habitat.
As leaves decompose they create a moist, sheltered environment that all kinds of creatures will be drawn to. Eventually - if left in a purpose-built pile or cage - the leaves will break down fully into a dark, crumbly humus-like material known as ‘leaf mould’.
Invertebrates and Insects
These creatures feed on and break down leaf litter before fungi and bacteria take over, slowly decomposing the material and helping to make nutrients more available for plants, trees etc.
This is the natural life cycle that is observed in forest environments, and by setting aside a leaf pile or making a ‘leaf mould cage’ you are looking to replicate it (for the benefit of your garden as well as wildlife!).
The rich variety of life that leaf litter attracts includes earthworms, millipedes, nematodes and springtails. Some will be taking part in the process mentioned above while others (such as ground beetles) are there to ‘hunt’ other invertebrates and organisms.
Burgon & Ball Lawn and Leaf Rake
View ProductWoodlice for example are known as nature’s ‘specialist recyclers’, feeding on damp, decomposing material; they are an important part of a biodiverse garden, and contrary to their reputation they do very little if any damage to plants and vegetables.
Ecologist Anja Murray recently pointed out that there are about 1,500 species of moth in Ireland, many of whom depend on leaf litter as a winter habitat, and that their falling numbers are partly related to unnecessary disruption of these habitats. Oftentimes their cocoons can be camouflaged to appear like dried leaves themselves.
Leaf piles provide a vital overwintering habitat for butterflies in their pupal or caterpillar stages, while some species of bumblebee will use leaf litter as nesting sites.
Of course it’s worth acknowledging that a decomposing leaf pile can also attract slugs - but a well-balanced biodiverse garden can also keep slug populations in check. Suggestion: have a gentle root around to see if you can spot some slug eggs in spring or autumn; then leave them at the surface for the birds to make off with.
Haxnicks Spike Leaf Picker
View Product
Birds
A leaf pile teeming with all manner of insects and invertebrates also serves as an attractive foraging spot for our feathered friends.
You will often see birds - such as blackbirds, thrushes or sparrows - having a good dig around to see if they can find insects, grubs, caterpillars and so on.
These foraging opportunities are doubly important in winter when other food sources are hard to come by; the leaf cover essentially keeps their dinner or snacks warm! Additionally, some birds will gather dried leaves to use as nest-building materials.
Hedgehogs and Frogs
The warmth of a leaf pile is seen as a perfect nesting spot for hedgehogs, who will then spend the winter hibernating, living off their fat reserves. If you’re setting up a leaf mould cage, allow a gap at the bottom for them to access it. They are also known to feed on leaf litter inhabitants such as ground beetles.
Frogs can also search for food among piles of leaves. It’s not their preferred hibernation spot, but they have been known to use the damp habitat created by massed leaves for shelter, or to hide from predators.
Long-Term Wildlife Friendliness
If you take the long view, dead leaves that are left to break down for long enough into leaf mould can be then used to enrich your garden soil. This in turn leads to healthier plant growth, whether you’re growing edible crops, herbs or ornamental flowers.
Healthier and more resilient plant growth means that you won’t be tempted to reach for chemical-derived fertilisers or pest control products, which can have harmful effects on wildlife and biodiversity. A garden with a rich, colourful variety of crops will attract pollinators, beneficial insects and a diverse array of garden visitors - leading to a relaxing background hum of activity.
