There is a growing movement to leave leaves on the ground, instead of gathering them to be disposed of.
The idea is to avoid sending bagged-up fallen leaves to landfills. Instead they will naturally decompose over the winter into rich organic matter. The matter also shelters pollinators and other insects.
Done correctly, leaving the leaves is one of the best ways to turn yard waste into free fertilizer, which is good for plants, the environment, and saving money. But it is important to consider the types of leaves that are falling and where they are landing.
Whole leaves should not be permitted to remain on walkways, where they could make the path dangerously slippery. They should also not be left on grass lawns, where they are likely to cause disease.
Although some grasses can handle a small amount of leaf waste, too much can threaten their health. In areas that experience snow cover, water would become trapped between grass and leaves. That could lead to mold and other fungal infections. In areas without snow, whole leaves that cover grasses block water and sunlight from reaching the soil below.
Many people choose to break up the leaves using a machine and let the pieces to fall between pieces of grass. Then the pieces break down further in the soil. However, this treatment can kill insects and their eggs.
Another method is to take the leaves off the lawn and spread them lightly to cover garden beds. The leaves mostly break down by spring and almost entirely by summer. But if not, they should be removed before spring growth begins.
Leaves also can be used to make leaf mold, a type of compost made entirely from leaves. Just pile them up in a corner, add nitrogen fertilizer, and water it to keep it from drying out. It may take a year or two, but the leaves will break down into a nutritious soil.
Some leaves prevent the growth of other plants. Black walnut, for example, contains a poison in its leaves that kills many plants, including hydrangeas, petunias, apples, peppers, tomatoes and potatoes.
Avoid putting leaves in beds if the leaves are especially large or thick, like those of oaks. Their slow decomposition rates could block sunlight and water from the soil and plant roots.
Fallen leaves are nature’s mulch. They build fertile soil, protect plant roots and shelter wildlife, in your garden, and elsewhere. Why waste that important resource?
I’m Dan Novak.