Every Autumn, I see piles of tree leaves waiting for the city trucks to come along and suck them up, to be carried off to the municipal compost pile. Hopefully they aren’t going to the landfill.
But if you’re a gardener, I sincerely hope that you’re saving those tree leaves for your garden. They can be used as mulch or compost and are an important source of nutrients for your soil.
According to The Rodale Book Of Composting: “Leaves are a valuable compostable and mulch material. Because trees have extensive root systems, they draw nutrients up from deep within the subsoil. Much of this mineral bounty is passed into the leaves, making them a superior garden resource. Pound for pound, the leaves of most trees contain twice the mineral content of manure. The considerable fiber content of leaves aids in improving the aeration and crumb structure of most soils.”
Composted tree leaves and similar organic material are excellent for lowering the pH of alkaline soil.
To use the tree leaves as mulch, chop them up with a lawn mower or shredder (because whole leaves tend to mat together), and then leave them weather in the open air for a few months. Chopping your organic material into fine pieces helps it decay much, much faster than leaving it whole. Leave them outdoors for a few months, because leaves contain growth-inhibiting phenols that should be allowed to leach away before they’re used.
Make Leaf Mold
You can also make leaf mold, which is extremely nutritious for your plants. Leaf mold is the end product of tree leaves decomposing in a moist environment, primarily by fungi. You know the thick, dark material that grows under the fresh leaves on the forest floor? That’s leaf mold.
To make leaf mold, rake your leaves into a pile and water them down. Then let them sit for two or three years. Yes, years. It’s probably a good idea to put them in a compost bin of some sort so they won’t blow away. Turn them once in awhile to make sure that anaerobic bacteria doesn’t build up and create a putrid smell.
But the simplest thing to do with those tree leaves is to shred them and throw them into your compost pile along with high nitrogen material (leaves are very low in nitrogen and will break down very slowly). Mix the leaves with kitchen scraps, grass clippings, manure, blood meal, etc. If your garden is fallow over the winter, work them into the soil now so they’ll decompose over the winter and early spring.
Rake ’em up and compost ’em! Don’t let those tree leaves go to waste.