Leave Your Leaves For a Healthy Yard

This autumn, let your leaves stay on the ground for natural benefits

Here in California, we don’t have the same fall season as they have in the northeast, where cooler weather, longer nights, and various leaf pigments produce a range of spectacular colors of tree leaves before it all falls to the ground. In the west, fall colors tend to be more of the golden variety, though dogwoods and black oaks offer red foliage throughout the season. 

As fall progresses and winter approaches, the leaves fall from the trees and gather on the ground.

Cindy Gerson, the UC Master Gardener of Napa County, wrote an article about this natural process in November 2023, describing the process of abscission, in which leaves change color on the tree, and a layer is created between a twig and a leaf. In fact, the leaves are not falling from the tree, but being pushed off by the tree. This process allows the tree to put its energy into root and structure growth during the colder months. And the fallen leaves continue to impact the environment in a positive way, while laying on the ground.

Now, any tidy groundskeeper in any residence may want to rake those piles of fallen leaves and dump them into the green bin for disposal, thus keeping the ground clean for the winter as it waits for the renewal of spring. Leaf blowers are a problem, causing air and noise pollution without providing a positive service, other than shuffling leaves around. By all means do not rake up your leaves and move them to a landfill, which can produce harmful gasses like methane—at the very least, find a municipal recycling center where the leaves can be transformed into compost and used by other members of the community. Benicia’s garbage and recycling collection are provided by Republic Services (republicservices.com/beniciaCA), which launched an organics program in 2022.

There are reasons to wait on cleaning those leaves from the yard, however.

According to the United States Department of Agriculture, fallen leaves on the ground create a natural mulch as they break down, fertilizing the soil of the yard and suppressing the growth of weeds. The piles of leaves also become a habitat for birds, lizards, insects, and many other creatures which keep pests away and increase pollination in your yard, which will increase the health of your garden each season. The vast majority of butterflies and moths come into existence during the winter, while bumble bees, snails, and worms also need the leaf mulch to develop.

The keys to healthy soil in your yard are microorganisms, and leaving your leaves to decay on the ground feeds the microorganisms in the earth. These microorganisms will make the soil in the yard healthier and next year’s plants will grow stronger. Also, as the leaves decay, they provide organic matter into the soil, which lessens the need for fertilizer. The organic matter increases biodiversity and water retention, and improves water quality. The best part of this, of course, is that your leaf layer doesn’t cost a dime, and is so much healthier for the environment than foreign fertilizers.

Leaves don’t need to be left where they fall, by the way.

You can chop them up with a lawnmower, and miniaturize your mulch. Leaves can also be moved between rows of crops or around fruit-producing trees, or to shaded areas that don’t produce as much vegetation. A layer of leaves should be at least a couple of inches thick to offer the ultimate impact in the soil and yard.

The leaves will provide comfort to your yard during inevitably changing temperatures, cooling the soil during unexpected hot spells—such as the record breaking temperatures the Bay Area experienced in early October. The leaf beds will also help keep some moisture in the ground during times of drought. When springtime does come, don’t remove your leaves right away—make sure to leave them on the ground until late in the season to maximize the impact they have.

A number of online articles about leaving your leaves in your yard address the social etiquette of discussing your lack of leaf cleanup with nosy neighbors who would prefer that your yard be spic and span in the fall and winter months. If this is an issue in your neighborhood, maybe refer your neighbors to the National Wildlife Federation website, which is packed with articles like “Leave the Leaves For Wildlife” (September 24, 2024), and let them know you are just doing your part to save the planet.

Or, direct them to a Visitcalifornia.com article such as “8 Perfect Places To See Fabulous Fall Colors” in the Golden State. A drive through Alpine County, Mono County, or over the Sonora Pass might bring the bigger environmental picture into focus.

One more thought:

Depending on the size of your leaf piles, they can also provide a playground for dogs—check out the YouTube channel Dog Named Stella to see a dog whose favorite activity is running full speed and jumping into a massive pile of leaves. Stella is adorable and loves her leaves!