Skip the Rake and Leave the Leaves for a Healthier, Greener Yard

Autumn's bounty of fallen leaves isn't usually a problem for lawns and gardens—mulching the ground with them helps to feed the soil for a healthier yard.

If you grew up in a neighborhood with lots of trees, chances are you had to put in plenty of hours each fall raking the leaves, bagging them up, and then sending them off somewhere, most likely to the landfill. And you were probably told that this was so the yard would look tidier and the leaves wouldn't kill the grass. This myth has probably sold more rakes and bags than anything else. And while raking may have enriched the pockets of neighborhood kids, the practice removes important soil nutrients, which homeowners then usually repurchase in a bag or jug of fertilizer from the local garden center.

Because we're older and hopefully wiser now, removing leaves—an important annual input to our local soil biology—and sending them elsewhere shouldn't make as much sense as it might have before we knew better. While it's at least partially true that excessive amounts of fallen leaves left in thick piles all winter can smother a lawn, leaving the leaves on the ground as mulch can be an effective soil-building method to support a healthy yard.

Benefits of Fallen Leaves

Fallen leaves—as an additional physical layer of organic materials above ground—provide food, shelter, and nesting or bedding materials to wildlife, as well as overwintering protection for insects, all contributing to a healthy yard. The soil beneath the leaves also benefits from this autumnal gift, as the leaves are essentially composted over time into nutrients that feed the grass crop the following year. But, leaves also feed microbes in the soil, which are the most important crop you can grow, considering that all plant life in your yard depends on healthy soil biology.

According to National Wildlife Federation Naturalist David Mizejewski, “Fallen leaves offer a double benefit. Leaves form a natural mulch that helps suppress weeds and at the same time fertilizes the soil as it breaks down. Why spend money on mulch and fertilizer when you can make your own?”

Maximizing the Benefits

However, leaving the leaves to lay where they fall in the autumn isn't the most effective way of maximizing their benefit, as sometimes they can pile up in areas where they may effectively smother a section of the yard. But, there are several ways to approach your leaf harvest, depending on your situation.

As one plant and soil specialist, Dr. Thomas Nikoai of Michigan State University, put it, leaving the leaves on the lawn is " ... not only not a problem, it's awesome." According to an interview at Christian Science Monitor, Dr. Nikolai says that mowing over the fallen leaves to turn them into smaller pieces will enhance the lawn's fertility, not kill it. And, while it's usually best to use a mulching mower or mulching attachment to convert the larger leaves into smaller-sized particles, virtually any mower can do the job; it's merely a matter of mowing over the leaf-filled yard a few times during the season.

However, if you're cultivating a tidier look to your lawn and don't want those pesky dried leaves getting in the way, you can rake them into garden beds, flower beds, or mulch around trees, either as-is or by using a bagger on your mower to collect them. Covering garden beds with a thick mulch in the fall can be an effective and simple way to build soil fertility and keep your yard tidier.

But, far be it from me to encourage you to use lawn equipment in a way that it's not intended. I've heard, however, that you can put leaves into a large trash can and then use your weed-eater in the can to slash the leaves into tiny bits for use as mulch.

Leaves can be a great additive to a home compost pile, and by keeping a leaf pile next to your compost, you can use leaves to cover layers of kitchen food waste throughout the winter. You can also use fallen leaves to reclaim marginal sections of a yard by building a huge leaf pile there and letting it sit all winter. By spring, the lower part of the leaf pile will have transformed into rich soil, while the middle and top layers will be perfect for mulch or a soil amendment for spring garden beds.

Leaf Drop-Offs

If none of these uses for fallen leaves work for your situation, you can look into local options for leaf drop-offs—places that collect yard waste at a central location and turn it into compost and mulch. Although this option requires raking and bagging, it keeps a potential natural resource out of the waste stream.

And if you're like me—always looking for sources of free organic matter to use as compost, mulch, and soil-building materials—you might want to put your name out there as a prospective drop-off location for neighborhood leaves. You can also contact the coordinators of the local leaf drop-off and ask about getting bags of leaves for free from the event (I've done this before and it's an effective and simple way to get free ingredients for enriching your soil).