How keep your soil moist with mulch

Keeping soil moist and warm while smothering weeds

An organic mulch, such as leaf mold, well-rotted compost, dry grass clippings, shredded bark, or buckwheat hulls adds humus and nutrients to the soil; inorganic mulches, such as plastic and gravel, add nothing, but they last longer. Apply an organic mulch after the soil has warmed up and your plants are tall enough not to be buried. Most mulches should be 2 to 5 inches thick; a 1-1.5 inch layer of sawdust is enough, however, and five or six sheets of newspaper make good cover. Weed the garden, fertilize it, and if the soil is dry, give it a good soaking before putting on the mulch. Do not mulch right up to a plant stem or a tree trunk; leave a small space around it.

At the end of the growing season, dig the mulch into the soil or rake it off and add it to the compost pile. Add fresh mulch in late fall for winter protection for perennials or bulbs. Lay black plastic mulch in early spring after preparing the soil for planting. It will quickly increase the soil temperature by several degrees. If the soil is dry, soak it first. Work on a windless day and anchor the edges of the plastic with soil or stones. Make slits for planting seeds and cut X’s in the plastic for transplants; poke more small holes 6 to 12 inches apart so that rain can seep in. With care, black plastic can last as long as three seasons.

A new kind of mulching material is a fabric like substance through which water and fertilizer can pass. It is expensive but needs no holes cut in it.