Take it easy: leave the leaves

By Don Davis
Published: October 29, 2008

Tree leaves are not garbage to be thrown away. Instead, they are a valuable source of carbon and other nutrients needed by your lawn.

You can depend on a steady supply of leaves every autumn, delivered for free if there are any trees in your yard.

Don’t put away your lawnmower too early, because it offers an easy and simple way to recycle tree leaves directly into your lawn. You can leave the leaves where they fall. No burning, vacuuming, blowing and raking are required.

Lawnmowers chop tree leaves into small pieces, which are taken from the surface of your lawn down into the soil by earthworms. Leaves pass through the bodies of earthworms, along with soil particles, and the result is worm castings. This material has greater fertility than soil, and it provides food for plants.

Your lawnmower is a “food processor for worms,” according to a yard care publication from Montgomery Co. in Maryland. It shreds, chops and pulverizes leaves, and makes them an abundantly available food option for worms.

Earthworms also create a system of tunnels in the ground as they burrow through your lawn. These tunnels allow air and water to enter the soil and stimulate lawn root growth.

Every leaf falling on your lawn can be recycled by “leaf mulching” with a lawnmower. Purdue University scientists did some research on leaf mulching and found that recycling two tons of maple leaves into a perennial ryegrass lawn caused no harm to the grass.

Although “mulching” lawnmowers are preferred for leaf mulching, the regular side-discharge mowers are also quite useful. The key is to start leaf mulching around the edge of your lawn and blow the leaves toward the center where they will be chopped repeatedly as you finish the job.

Here are a few other tips for leaf mulchers:

- Go slowly. This maximizes the contact between leaves and mower blades.

- Do leaf mulching whenever the leaves pile up to a depth of one inch. Grass will suffer if you let too many leaves cover it for too long.

- Dry leaves are easier to chop up than wet ones, though there will be less dust in the air if leaves are chopped when slightly moist.

- Wear a dust mask to cover your nose and mouth. Safety goggles are also recommended. Dust and mold spores will be airborne when you are leaf-mulching.

- Remove sticks, branches and other debris before leaf mulching.

- Check your mower’s owners manual to see if it contains any advice on leaf mulching.

- Leaves are beneficial, but they are not the same as fertilizer. Cool season grasses, such as fescue, rye and bluegrass, need nitrogen fertilizer every autumn. Give your lawn a dose of it this month and next.

Master Gardener classes set

Yard care is one of many subjects covered in the 2009 Master Gardener program, beginning Feb. 3. Applications are due by Jan. 9. Call the Lynchburg Extension Office at (434) 455-3740 or by visiting www. hcmga.com.