Express-News Weekly Column Saturday, November 18, 2000 Submitted by Calvin Finch, Ph.D.,
Director of Conservation, SAWS, and Horticulturist

LEAVES AS A RESOURCE

Remember how much fun it was to rake the leaves into huge piles and play in them until it was time to bag or burn them? Times have change. We can still rake our leaves, but it is environmentally incorrect to have them take up valuable landfill space or to pollute the air as they burn.

The good news is that leaves are too valuable to waste. Rake them up if you need the exercise or you want your children or grandchildren to have the opportunity to play in the piles, but afterward use them to improve your landscape.

Leaves make great mulch. It does not matter what kind. In a few weeks pecan, red oak, cedar elm, hackberry, mulberry, sycamore, bur oak, chinkapin oak and the other deciduous trees will drop their leaves. Piled four inches deep over the roots of newly planted trees, leaf mulch will increase the tree's growth rate by as much as forty percent over the same tree with grass growing against the trunk.

Used three or four inches deep in the shrub and perennial border, leaves provide an ideal place for ground-feeding birds like towhees, American sparrows and thrashers to search for seeds and insects while the mulch conserves water, insulates the soil from cold or hot, and reduces weeds.

Leaves are my favorite mulch in the vegetable garden because they can be incorporated into the soil after every crop. In fact, some vegetable gardeners count on the autumn leaf fall for their winter garden and the spring live oak leaf drop (February) for the spring garden. Leaves applied four inches deep between rows in the vegetable garden make excellent pathways while performing their duty as mulch. The soil is not compacted as you work the rows and no mud is tracked.

In my neighborhood there are several Master Gardeners. Early in my history in the neighborhood I made the error of collecting bagged leaves from the curb belonging to some neighbors. I believed I was saving precious landfill space and would be improving the soil in my yard. I was quickly alerted that the leaves "were already spoken for" by the other gardeners. That may not be the case in your neighborhood. Use any extra leaves you have and those unwanted by your neighbors to make compost.

Make a structure of a stiff hog wire about five feet in diameter and three feet deep. Fill the structure to overfilling with leaves salted with about five pounds of lawn fertilizer. In four or five months the leaves will decompose to a homogenous, fresh-smelling, soil-like compost that will work wonders to revitalize your container plants and raised beds or flower gardens.

To speed up the decomposition and get some exercise, remove the wire from the pile and move it a few feet away. Reshape the circle, clip the wire ends together, and shovel the pile from the old location to the new location. The act of turning over the pile incorporates air into the organic material and mixes the materials. Do this mixing every two weeks and dampen the pile after the mixing and you can have the compost ready for use in six weeks. It will work so fast that you will be able to feel the heat as the leaves break down.

If you are not into collecting your leaves, one of the best ways to take advantage of their value to your landscape is to let them decompose on the lawn. In a damp, mild winter they will melt down to nothing in eight to ten weeks. Speed up this process by mowing the leaves and leaving them on the lawn. Leaves are not as valuable to the grass as grass clippings, but they do provide small amounts of nitrogen, phosphorous, potassium, and all the micro-nutrients. Most importantly, however, the decomposing leaves serve as food for beneficial microorganisms and contribute to soil health.

The most valuable things in life are free, include leaves on that list.