Cleaning up autumn leaves can be a lot of work, especially if you have a large lawn with lots of trees. It's tempting just to let the leaves stay on the grass. But the reality is it's in your lawn's best interest to clear away those leaves. You can, however, simplify the task or use the leaves to improve next year's garden.
Leaves that aren't removed from your lawn block essential sunlight and air from reaching the grass. The problem becomes worse when it rains or snows, turning fluffy layers of leaves into soggy mats. The lack of light and air circulation can cause turf diseases or, in a worst-case scenario, can even smother and kill the grass.
One of the easiest ways to manage your leaves is to mulch them. Mulching leaves is simple: Just shred the leaves with your lawn mower as much as possible soon after they fall. Check to be sure that the mulched leaf material left behind is not excessive. It should blend in nicely with the turf and not accumulate so much that it covers the grass blades, causing the lawn to suffocate.
For those who insist on a spotless lawn year-round and might be concerned about what the neighbors will think of the brown leaf bits the mower leaves behind, don’t worry. The shredded leaves will filter through the grass and disappear from sight. In northern lawns that go dormant in cold weather and turn a brown color, the shredded leaves might even blend right in. A benefit of mulching is the organic leaf matter can help to feed lawns, and it might even suppress some weed growth.
While mulching is the easiest option to manage fall leaves, it's not always appropriate. For instance, sometimes fallen leaves harbor disease, which can survive the winter if left as leaf mulch on a lawn and then reinfect plants in the spring. These diseases are often host-specific, meaning they only infect a certain type of plant (e.g., deciduous trees but not grass). So while the leaves might not necessarily harm your grass, they can lead to nearby plants becoming infected. Thus, raking them off your lawn is the best option.
In some communities, residents rake leaves into the streets, and city workers sweep them up. The problem with this strategy is many leaves are washed into sewers where they make their way to streams and other waterways. There they release nitrogen and phosphorus into the water, which encourages algae growth. And excessive algae growth depletes the water of oxygen and kills fish and other aquatic life. If you want to help prevent this, bagging your raked leaves in yard waste bags is the way to go.
Another option to remove leaves from the lawn but still turn them into a useful product for your garden is composting. Composting does require some patience. But there are two things you can do that will guarantee success when composting leaves:
- Grind or shred your leaves before composting them. This will cause them to break down faster.
- Add extra nitrogen to your leaf compost, which also promotes faster breakdown. Manure is the best nitrogen supplement, and a mixture of five parts leaves to one part manure will break down quickly. If you don’t have manure (and many gardeners don’t), nitrogen supplements such as dried blood, cottonseed meal, bone meal, and granite, will work almost as well.