Mulching

Mulching cools, protects, and enriches the soil.

Mulching involves placing a layer of material around plants. As mulch decomposes, it adds organic matter to the soil. This provides important nutrients for plants and an ideal environment for earthworms and other organisms that help enrich the soil.
Mulching can recycle yard wastes and improve your soil. Mulch protects soil from erosion, prevents weed growth, conserves soil moisture, stabilizes soil temperature, reduces compaction, and keeps any fruit or vegetable that touches the ground clean and dry.

Mulch Material

The best place to look for mulch material is in your yard. Grass clippings and leaves work well for mulching if they are dry and weed free. Avoid adding clippings to your vegetable garden from lawns that have been treated with weed killer within the last two mowings. Compost makes an excellent organic mulch material. It adds nutrients to the soil and has a natural appearance. Wood chips and bark work well around trees and shrubs and make attractive walkways.

Applying Mulch

Insulate the root zone and lower evaporation rates if you liberally apply mulch. Be careful not to smother the plants. As the mulch breaks down, add more material to the top throughout the growing season. After harvest, work the mulch into the soil to integrate the organic matter, or leave it on the surface to decay naturally and be carried into the soil by earthworms. Apply mulch when plants are established and soil is warm. First, water your garden well. Then place a layer of mulch around the plants. As a rule of thumb, mulch should be kept five inches away from the trunks of shrubs and ten inches away from the trunks of mature trees. Thickness of the mulch layer varies for each material, listed below are common materials:

Free mulch is available to the public on Oahu, visit: www.opala.org.

Source: "Hawaii Backyard Conservation" (PDF), The U.S. Department of Agriculture.