When most of us were growing up, autumn was the season when the trees dropped their leaves and we had to rake them all up to keep our yards healthy and attractive (a chore that often resulted in groaning and grumbling from both homeowners and their teens, who were often conscripted for the task).
But times change…and we’ve now learned that not only is raking or blowing away every last leaf a lot of work, but it can actually be healthier for your yard and garden to leave fallen leaves where they fall.
According to Leaf Mulch Info – Learn About Mulching With Leaves, by Bonnie L. Grant, a Certified Urban Agriculturist, “Dead leaves should actually be looked upon as a boon. Leaf litter mulch in gardens has numerous attributes and mulching with leaves is an inexpensive and renewable way to achieve garden gold.” According to Grant, “This organic mulch…improves the soil’s fertility and its organic content. Mulching with leaves is a win/win in many situations where you want more rapid decomposition and is generally a free commodity to anyone that has deciduous trees.”
So in other words, a layer of leaves in a garden bed is like a layer of any other kind of mulch – it helps hold moisture in, keeps weeds down, and as the leaves decompose, they sift in, mix with other elements and nurture the soil.
But there are other benefits, too. For example, writer Jessica Walliser explains in “Six Reasons NOT to Clean Up Your Garden This Fall,” a layer of fallen leaves provides cool weather shelter for bees, butterflies, ladybugs and other insects important to the overall health of your garden and our general ecology. For example:
“Many of North America’s 3500-plus species of native bees need a place to spend the winter that’s protected from cold and predators. They may hunker down under a piece of peeling tree bark, or they may stay tucked away in the hollow stem of a bee balm plant or an ornamental grass. Some spend the winter as an egg or larvae in a burrow in the ground. All native bees are important pollinators, and when we remove every last overwintering site by cutting everything down and completely cleaning up the garden, we’re doing ourselves no favor. We need these bees, and our gardens can provide them with much-needed winter habitat.”
Of course our southern California winters aren’t as harsh as those in many other parts of the country, but they are generally cooler and wetter than our summers, and bees are just as valuable to our gardens and habitats as they are anywhere else.
And finally, as Walliser also notes in her article, more insect life in the garden means more food for birds, predatory insects and other pollinators…another big benefit.
“Insect-eating birds, like chickadees, wrens, titmice, nuthatches, pheobes, and bluebirds, are very welcome in the garden because they consume thousands of caterpillars and other pest insects as they raise their young every gardening season. Not cleaning up the garden means there will be more protein-rich insects available to them during the coldest part of the year. These birds are quite good at gleaning “hibernating” insects off of dead plant stems and branches, and out of leaf litter. The more insect-nurturing habitat you have, the greater the bird population will be. Your feathered friends will also appreciate feasting on the seeds and berries they can collect from intact perennial, annual, and shrub stems. Song birds are one of the best reasons [to] skip the garden clean up!”
But all of this is mostly about garden beds. What about big grassy lawns (for those who still have them)? Traditional wisdom has always said that leaving fallen leaves on the lawn will kill the grass. Well, it turns out thinking there has changed, too, according to “Leave the Leaves: How Doing Less Yard Work Helps the Environment,” published in the Christian Science Monitor:
“Michigan State researchers began studying the effect of leaves on lawncare in the early ’90s. They piled leaves onto grass plots to see how much it took to kill a lawn, and they discovered that leaf-covered lawns were among the first to turn green in the spring.
“It’s not only not a problem, it’s awesome,” says Dr. Thomas Nikolai, a specialist in Michigan State University’s plant and soil science department, in an interview with The Christian Science Monitor.”
So go ahead – spend a bit less time this fall raking or blowing away every last leaf…and a bit more time enjoying the season. Of course, if you or the teens want to rake the leaves into piles for jumping in, we can fully endorse that time-tested autumn tradition. (And we might come join you!)