Various Mulches Available
Mulch is defined as any material spread on the garden to protect root plants from heat, cold or drought; to reduce problems with weeds; and to keep fruit clean. Mulching materials can be:
Clear plastic - Clear plastic warms the soil more than most other mulches, stimulating weed seed germination and growth. It also can be laid over seeded rows to stimulate early vegetable seed germination. Remove the plastic as soon as seedlings emerge. If weeds are not a problem, clear plastic is an excellent mulching material.
Black plastic - Black plastic makes the soil warmer early in the season and greatly reduces the weed population. Black plastic, however, will not control nutgrass. Adequate soil moisture should be available when black plastic is applied. Cut holes through the plastic after it is applied over the bed to allow for seeding or transplanting. Water by using drip systems or water soakers beneath the plastic, by furrow watering or by sprinkling. If sprinklers are used, it may be necessary to cut T-slits in the plastic for water penetration.
Paper - Various types of paper are used as mulches, with newspaper being by far the most common. Several sheets of newspaper laid flat over the surface of the garden row work well as a mulch. However, paper reduces soil temperature. Paper mulch used early in spring when the soil is cold causes delayed maturity of many garden vegetables, such as tomatoes, peppers, squash, etc. For these crops, paper can be applied after crops are growing and the soil has warmed up. Paper mulch will not delay cool-season, spring-planted crops such as lettuce, broccoli and cabbage, as much as warm season plants. As with black plastic, apply paper when the soil contains adequate moisture. Unlike plastic, paper deteriorates and does not have to be removed at the end of the gardening season.
Organic mulches - Organic mulches are by far the most common. Benefits of organic mulches are gained primarily in summer because they reduce soil temperature and save soil moisture. Do not use organic mulches too early in spring. If applied to cold garden soils, the soils warm up more slowly and crop maturity is reduced. Organic mulches prevent soil crusting, control weeds, prevent erosion, lessen fruit rot, conserve moisture and reduce soil temperatures during summer.
After the soil warms, apply organic mulches to a depth of 1 to 2 inches around growing plants. With organic materials such as sawdust, leaves, rice, hulls, etc., it usually is necessary to increase the amount of garden fertilizer by about one-fourth to compensate for the nutrients used by microorganisms during the breakdown process. At the end of the season, turn organic mulches under to improve the soil's physical condition.¶