Leave the Leaves
IN AUTUMN, TREES DROP A VALUABLE GARDEN RESOURCE
RIGHT AT YOUR FEET.
by JULIE BARE
FALL FOLIAGE IS BEAUTIFUL TO LOOK AT when it is on the trees, but when the leaves pile up on the ground, many homeowners (and their hired
landscaping services) rake or blow every single one off their yards, often loading them into plastic trash bags that end up in landfills. But with just a little work, those leaves could be transformed into garden gold that can build your soil’s fertility, protect your plants, provide habitat for beneficial insects, and even improve the lawn. Here’s how you can put leaves to work in your yard.
Spreading a layer of leaves on vegetable and perennial beds will moderate soil
temperature changes, preventing new transplants from heaving when the groundfreezes and thaws in winter. As leaves decompose, they add nutrients for the soil’s food web, which comprises the microbes, fungi, and earthworms that nurture plants underground. The organic matter added as the leaves break down improves the soil’s water retention capacity and helps loosen up heavy clay. The leaves will also block sunlight and prevent weed seeds from germinating in spring. Adding a 3-inch thick layer of leaves as mulch will provide all of these benefits.
You can turn leaves directly into a potent soil amendment by letting them
decompose before adding them to your garden. Leaf mold contains nutrients that are readily available to plants, so it’s useful when you are sowing vegetable seeds or putting in transplants. To make leaf mold, you can pile the leaves—shredded or whole—in a cylinder of chicken wire or in a plastic bin or bag (poke the latter with a few holes to allow oxygen in). Moisten the leaves periodically to facilitate the decomposition. Check on them after about three to four months to see if they’ve begun to break down. You can use the leaf mold in your garden when it becomes dark and crumbly.
Often referred to as “black gold” by gardeners because it has so many
applications, compost is useful as a fertilizer, soil conditioner, potting soil, and
disease deterrent. If you have yard and garden waste and vegetable scraps from your kitchen, you can combine them with fall leaves to make your own compost. When brown and dry, leaves are high in carbon and an ideal complement to the green, nitrogen-rich waste from your garden prunings and kitchen parings. Keep a pile of fall leaves next to your compost pile and mix in a few handfuls whenever you add the scraps.
Removing all the leaves from your lawn and then spreading bagged fertilizer on the grass doesn’t make sense. Decomposing leaves feed grass with the key nutrients it needs in fall. Leaves used as mulch on the lawn also decrease the number of dandelion and crabgrass sprouts that come up the next spring,
according to the Michigan State University extension service. Turning fallen leaves into grass fertilizer is as simple as running them over with a lawn mower, shredding them into small pieces that you won’t notice after a few days. The shreds gradually settle onto the soil surface and break down over winter.
Even if you like to neaten up your landscape in fall, consider letting leaves remain around the base of trees such as oaks, willows, cherries, pines, and poplars. Leaf litter is critical habitat for many moths, butterflies, bumblebees, lacewings, beetles, and fireflies as they complete their life cycles during their months of dormancy.
Creating this habitat for insects will also attract birds that eat them. In addition,
leaf litter provides refuge during the winter for turtles, toads, and other insect-
Julie Bare is a landscape steward at Refugia Design.
This article first appeared in Grow Magazine from the Pennsylvania Horticultural Society (PHS). Visit the PHS website at https://phsonline.org
Want to learn more about critters that benefit from your doing less fall clean-up in your yard?