Plant Answers

LEAVES ARE VALUABLE

PRIMETIME NEWSPAPERS WEEKLY COLUMN
Week of November 19, 2001
By Calvin Finch, Conservation Director, San Antonio Water System, and Horticulturist

The leaves are dropping from deciduous trees. There are many options for leaves.

In the old days we would rake up the leaves, make large piles, and after the kids played in the piles for a few days, they would be burned or bagged for the landfill. Today, however, it is environmentally inappropriate to waste leaves by burning or bagging them. Burning is illegal in most communities because of air pollution and sewer concerns, and bagging should be.

Leaves offer small but important amounts of nitrogen, potassium, and micro-nutrients for your soil. More importantly, leaves and other organic material contribute to soil structure and water conservation. If they are bagged to be hauled to the landfill this potential resource becomes a waste material that must be hauled, and then fills valuable landfill space. It is harder and harder to find someplace to dump our wastes; leaves do not need to be part of the mix.

Instead of bagging your leaves consider the following options:

Let the leaves decompose on the lawn where they drop. Unless the leaves are deep, they will decompose and disappear within a month or six weeks. To speed up the process, mow the leaves. The smaller pieces decompose very quickly.
Collect the leaves by raking or with your mower's bagger to use them as mulch. Three or four inches of leaves over the roots of newly planted shrubs and trees saves water and controls weeds with the effect of increasing the plant's growth rate. The same leaves on the roots of established plants reduce watering, keep soil cool, reduce chlorosis and some diseases, and help control weeds.
Leaves make ideal paths in between rows in your vegetable garden. The covered rows provide all the benefits of mulch described in the previous option, plus prevent compaction when you must walk in the garden. The leaves can be tilled into the garden soil to improve soil structure every season.
Compost the leaves. Place the leaves in a pile, add a few cups of nitrogen fertilizer and the leaves will decompose to a homogenous, clean soil enricher that will work great in your flower pots or garden beds. For gardeners wanting to get serious about compost, the Texas Cooperative Extension offers detailed instructions on how to make compost in several weeks time. Send a self-addressed, stamped envelope to Compost, 3355 Cherry Ridge Dr., Suite 212, San Antonio, TX 78230
Give the leaves to the neighbors. If you are not interested in taking advantage of the resource yourself, share the leaves with a neighbor who can use the leaves in their garden.

All the leaves are useful, including pecans and oaks. The chemical and physical structure of leaves is different depending on species, but that only means that some decompose more slowly and the nutrients contributed are different.

If you are not impressed with the environmental and gardening arguments, consider the practical issues. It costs tax dollars to haul the leaves and it uses scarce landfill space for a material that can stay in our yards. Someday, we may have to put new landfills dumps in the neighborhoods that produce the most garbage.