It’s that time of year already. Autumn … or fall, if you prefer, a bittersweet season when summer heat retreats and leaves begin their graceful descent to the ground. So it’s also time for me to cast a watchful eye on my neighbor down the street.
Every fall “Neighbor Joe” mulches his fallen leaves with a lawnmower. He then piles the mulched leaves at the curb for the county’s Snuffaluffagus contraption to vacuum up and cart away. As soon as I notice Joe’s heap of freshly chopped leaves I tip-toe over with my wheelbarrow and seize the gold (and brown and rust) treasure, and quietly steal away with it. Sure, I’ve got leaves falling on my own property but I rescue Joe’s because his are perfectly prepped and primed for tossing into my garden. One simply cannot have too many leaves.
Joe could, of course, let his mulch-mowed leaves remain on his lawn to slowly feed his expanse of turf, and reward his plant beds as well with a decent layer of the bounty. But Joe is like almost everyone else in my neighborhood who rakes or blows their leaves to the curb. They all want the outward appearance of a tidy yard. If they were aware of the multiple benefits of leaf litter, might they instead decide to keep their leaves on their property? Possibly. Perhaps.
Leaves, twigs, logs and other plant material positively affects what’s above and below ground. They’re an integral part of a complex food web.
Decaying leaves feed, protect, and insulate plant roots. They provide food for essential decomposers like earthworms, bacteria and fungi — and decomposition naturally contributes to the creation of rich topsoil. Leaf matter also makes life better for all kinds of animals like insects, amphibians, small mammals and birds. I’ve often observed our white-throated sparrows and robins scratching through layers of leaves in search of tasty treats and eastern red-backed salamanders lounging under the moist leaves in early spring.
Throughout all seasons leaves are the perfect provider of food and habitat for insects in various stages of their life cycles: insects such as butterflies, moths, bumblebees, beetles and leafhoppers. And who wants to deny leaves to leafhoppers?
All these leaf-exploiting creatures are needed to feed higher links in the wildlife food chain.
Perhaps the single most important reason to let nature do things her own way is to support the magnificent trees that shed those leaves. Trees and turfgrass don’t play well together — the competition between the two is fierce. The nutrient-absorbing roots of trees and grass occupy the same space and studies begun in the 1960s show that trees don’t grow well when their roots are covered over with lawn. Those pristine lawns devour the nourishing food and moisture trees need to survive and thrive. Leaf litter gives it back. Applying a large area of decaying organic material (from all parts of a tree) is a must-do gardening task and more recently an American National Standards Institute recommendation for arborists. How’s that for an endorsement of the dead stuff?
Want to see what happens when leaves are allowed to do what comes naturally? Check out this timelapse video of our backyard one spring.
February 2022 update: Leaves should be kept intact in order to provide full ecological functions. There is no science to support the benefits of chopping up fallen leaves and returning them to the landscape.