Leave No Leaf Unturned
From the Avant Gardener
September 1999.
Reprinted in the December 1999 issue of The Charleston Rose.

Ounce for ounce, leaves are richer in minerals than any other plant material. Wise gardeners have many ways of taking advantage of fall's fallen bounty.

Leaves can simply be allowed to accumulate on bare soil under trees and shrubs, or raked there. Many woody plants which are doing poorly will be revitalized by having several inches of leaves piled over their roots, preferably mixed with loose materials like straw to reduce matting. For vegetable and flowerbeds, leaves are best shredded and at least partially decomposed, since growth-inhibiting allelopathic compounds are released during their initial decomposition. On lawns, leaves can be mowed to nourish the soil and grass.

Left alone, piles of leaves will become leafmold in two to three years. The process is speeded by shredding them, adding some nitrogen fertilizer, and keeping the pile moist; turning the pile every three or four days will produce leafmold in three weeks. The same methods work in a large closed plastic bag kept in a cellar or garage.

Lacking a shredder-grinder, a rotary mower will shred leaves efficiently if run into a pile at an angle; so will a string trimmer if the leaves are placed in a large garbage can. Shredded leaves are easily applied to evergreen groundcover and perennial plantings by pouring them over the plants and brushing the foliage gently to move them down to the soil.

If leaves and a variety of other wastes are plentiful, any area of poor soil, from sand to heavy clay, will be improved by building a compost heap on it. A 3-foot mound will settle to about one foot high by spring. This can be planted as a raised bed, or the compost can be tilled in, or it may be removed for use elsewhere as mulch.

Leaf-chunk mulch is a new idea. Leaves in a pile or bin are trampled down to compress them, then in spring chunks one inch thick are lifted with a fork and used as mulch. Leaf-chunk mulch will last at least one season, and is not unattractive.