Did you know that fallen leaves may be the most precious harvest you will ever reap on your property? Fallen leaves can be turned into leaf mold by the slow action of fungi. Leaf mold is a beautiful, organic, locally created compost that can be used as a mulch or mixed into potting soils. Because leaves are broken down by fungi, not bacteria (as in traditional compost), the process is slower but the payout is larger. Leaf mold increases the survival of the beneficial microbes that help plants withstand disease pressure. For a science-backed look at the benefits of leaf mold check out this article from Urban Agriculture and Regional Food Systems.
Leaf mold is not sold commercially. The only way to get it is to make it yourself. Check out this article from Gardener's World to learn how to make leaf mold at home.
Leaf cage, compost heap and wormery at the Royal Horticultural Society garden at Wisley Image Credit: Rowan Adams, CC BY-SA 4.0, via Wikimedia Commons
Yet, there is an even easier way to utilize fallen leaves. You can make leaf mold (and save many invertebrate lives) simply by blowing fallen leaves into your garden beds without first shredding, mowing, raking, or otherwise collecting. The intact leaves act as mulch over winter, slowly breaking down and improving the soil. Invertebrates and other small creatures overwinter in the safe cover of the leaves. By spring, bulbs and perennials happily peep through the remaining leaves. By summer, the soil is loose, crumbly, alive with worms, and the leaves have all but disappeared. By fall, it’s time to start the entire process over again. Over the last few years, we have not had to mulch beds where leaf fall has been heavy enough. Hurray!
This year, we planted nearly three hundred mostly native trees and shrubs in the hopes of providing shelter for more creatures and more leaves for the gardens.
Yet, there are potential downsides to this method and it should only be used where appropriate. Overly thick layers of leaves can block air and water from penetrating the ground, or may lock in too much moisture, depending on the year. So, it is best to use this method of mulching only in areas where plants are already adapted to growing under leaf litter. Covering a sun loving plant like an Echinacea that is used to growing in open prairies would not be a good idea, but perennials like Hostas and Heucheras and understory shrubs like Lindera benzoin (spicebush) and Hamamelis (witch hazel) love it.
Finally, the ‘no shred’ method should only be used with smaller sized leaves: beech, betula, ornamental maples, etc. You do not want to leave very large leaves like sycamore, oak, or magnolia whole.
Sycamore leaf (left) vs Betula leaf (right)
