Why you should leave fallen leaves alone

There is one simple thing you can do this time of year to help all the animals living or visiting your property stay healthy during the winter months.

And this simple thing: “Nothing.” Instead of picking up fallen leaves, simply leave them alone.

Once upon a time, the ideal lawn was a strict patch of grass; Crabgrass, dandelions and other weeds cannot be grown. It was regularly mowed and fed with a mixture of fertilizers and herbicides. Autumn leaves were considered an unsightly mess that formed heavy mats during wet winters, killing the grass underneath. In the spring they were raked and bagged to be used as mulch, or sent to a landfill, or worst of all, burned. It was expensive to maintain and a lot of work.

As we’ve learned over the past 60 years since the environmental movement has gained momentum, raking leaves has also removed the comforting blanket of fallen leaves that protect many of the creatures that need them to survive our cold, wet winters.

In their 1974 book Biological Control of Plant Pathogens, scientists Kenneth Baker and James Cook wrote that “man must learn to visualize the pathogen on his crops as a partner in a feast, in front of himself and in view, and as part of the scene as he is.” and most likely has a residence permit. Each organism is as much the center of its own universe as a person considers himself to be.”

This understanding has led to widespread understanding that biodiversity is the key to a healthy ecology. The more creatures in a habitat, the stronger the fabric of life. This includes all the so-called “bad” bugs, blights and disease-causing organisms, as they are food or contribute to the creation of food for all the good guys.

The old-fashioned “perfect lawn” supported only one basic form of life: grass. In almost every other way it was a monocultural desert. That’s why it took so much work to maintain. This would not be possible without significant input from the homeowner.

The beauty of a healthy environment is that it sustains itself once you start it, just as nature in the wild sustains itself. As Masanobu Fukuoka said in his book The One Straw Revolution: “The right question for a farmer or gardener is not, “What should I do next?” but “What can I stop doing?”

Well, you can stop raking the leaves.

The leaves contain all the nutrients the plant needs to build tissue. So when the leaves fall, fungi, molds and microorganisms in the soil begin to digest them, turning the leaf litter into soluble forms of the same nutrients that the plant will recycle to create next year’s tissue. (This is what your body does when you eat a salad.)

Fallen leaves provide important cover

What happens if you remove leaves every year? You remove last year’s nutrients, depleting the soil year after year, until finally the soil is depleted and everything that grows in it loses health and strength. By leaving leaves to lie where they fall, you provide the many insects that pollinate, care for and inhabit our gardens and landscapes a safe, protected and, most importantly, moist place to thrive in the early stages of their development.

Butterflies and moths may begin overwintering as eggs but then develop into larvae. The leaves help protect their vulnerable bodies from predators such as birds and mice. But there are usually plenty of spare tracks. A pair of nesting tits can feed their young 4,000 or more caterpillars before they are fully fledged, and even more before they take their first flight three weeks later. The surviving caterpillars can then pupate and surround themselves with a chrysalis or cocoon, giving them greater protection in the coming winter, and they prepare to emerge from the safety of the leaf litter as adults in the spring.

Common insects in our gardens come in two main types. One of them is a herbivore. The other is insectivorous predators that eat herbivores. If your garden is populated primarily by herbivores, you have a problem. Without a full supply of predators, plant eaters can multiply and destroy your crops or ornamental plants. Many insects of both types overwinter under leaf litter, so by removing leaves, you eliminate both the herbivores and their predators. So, who were the first insects to colonize the garden? Not predators, since there are not so many herbivores to feed on. What about herbivores? The garden is a rich buffet of edible crops and ornamental plants. Lots of food for the bad guys. Thus, by removing leaves, you are creating problems for your plants and working for yourself that can be solved by using pesticides. But not only do pesticides further upset the balance of power in your garden, they can destroy other ecological systems besides insects.