These days, when I walk the streets of my neighborhood, I almost drool. Dead leaves cover everything, piling up on the sidewalk, in the street, on the cars, on my neighbors’ yards. I almost feel like shutting up and keeping all that “brown gold” to myself!
However, I’m generous by nature and anyway, there is a virtually unlimited supply of leaves… more than enough for any gardener. As regulars of The Laidback Gardener already know, autumn leaves are a gift from the heavens (literally) for our gardens. We can shred them with a lawnmower and they’ll feed our lawn, we can harvest them to mix into our compost, we can even leave them in place in our flowerbeds (when they’re small or shredded) and they make a wonderful mulch that protects roots from the winter cold, prevents erosion, retains soil moisture and decomposes to nourish and improve soil structure. Wow! Now you understand why I call it “brown gold”?
But there’s another way to use fallen autumn leaves, one that requires a little more patience, all right, but is very useful when you’ve got too many: leaf mold. Also known as leaf compost, It’s simply leaves decomposed by fungi. It is dark brown, almost black, reminiscent of the color of earth, and emits a forest-like scent.
It can be used as a mulch, on the surface, or as compost by mixing it into the soil. I find it a good substitute for black cedar mulch because of its earthy appearance, and it has the advantage of nourishing the soil as it decomposes, unlike cedar mulch, which resists decay. A beautiful and nourishing mulch? And it’s free!
Making Leaf Mold
Composting leaves requires only a little more effort than collecting autumn leaves, as you already do. In fact, come to think of it, maybe it takes even less effort, since you won’t have to bag the leaves. You all know how easy it is to bag leaves, don’t you?
Here’s how to make leaf mold
- Harvest the leaves;
- Shred leaves with a lawnmower, vacuum shredder or garden shredder. Or use the old laidback gardener’s trick: put your dry leaves in a bin and shred them with an edger!
- Put the leaves in a bin or leaf silo, ideally in an area with little sunlight so that the pile doesn’t dry out;
- Let the leaves to decompose for a few months or up to two years. The more the leaves decompose, the faster the nutrients will be available for your plants.
If you have room at home, make two piles and alternate each year. When one pile is ready, fill it again with leaves in the autumn; the previous year’s pile will be ready the following season. This is an excellent product to use in spring to hide perennials that have been left in the garden in autumn.
Unlike regular home compost, you don’t need to add green materials with a high nitrogen content, but leaf compost will take longer to decompose for this reason. There’s nothing to stop you making both types of compost if you have the space and enough leaves!
Benefits of Leaf Mold
Leaf compost has all the advantages of compost, but also those of mulch. The organic matter it contains improves soil structure. It improves the soil’s ability to retain moisture, but also helps drain it when there’s too much water. It will help aerate the soil, which is necessary for the root health of plants.
Like regular compost, leaf compost introduces microorganisms into the soil, including bacteria and insects, as well as fungi. These play a number of roles in the soil, including forming associations with plant roots to make nutrients more accessible. Leaves contain the main elements needed by plants, such as nitrogen, phosphorus and potassium, as well as secondary elements like calcium and magnesium. What’s more, it’s a good alternative to manure or composted manure, which often contain too much phosphorus; composted leaves are better balanced.
What’s more, the microbial life contained in this type of compost acts as a natural pesticide, helping to control populations of organisms harmful to plants.
And don’t forget that when leaf mold is placed on the soil surface in a 7 to 10 cm layer (4 inches), it acts as a mulch with all the benefits of mulch: protection against erosion, better soil moisture management, weed control, etc.
Other Uses for Leaf Compost
Leaf mold could also be a substitute for the sphagnum peat moss used in potting soils and substrates. However, current scientific studies on the subject are insufficient to validate its potential. That said, leaf compost is already being used by some agricultural producers for transplanting seedlings.
If you decide to try this method, be sure to sift the compost before use to remove any larger pieces that haven’t had time to decompose.
Leaf mold is another option for using your dead leaves. Just don’t tell your neighbors! Let them collect their leaves and bag them up at the roadside. Then you can steal them and make mulch and compost galore without having to lift a finger!