Is it Good to Put Mulch Around Your Vegetable Garden?

Controls Weeds

• Weeds compete with vegetables for available resources, such as water, soil nutrients and oxygen. They also provide habitat for harmful insects pests that may eat vegetables. Mulch creates a physical barrier for emerging weeds and creates unfavorable conditions for weed seed germination. Annual weeds need sunlight to germinate and grow. Small perennial weeds are also suppressed by a mulch layer of black plastic or newspaper. Weeds that spread by rhizome may be easier to pull up in soft, moist mulched soil.

Improves Soil

• Organic mulches add nutrients to the soil as they decompose. Mature compost used as mulch provides a slow-release of the 13 nutrients plants need to grow and thrive. Other mulch materials, such as straw, leaves, peat moss, grass clippings and ground corn cobs decompose slowly over the summer growing season and are then incorporated into the soil. Mulch dug into soil at harvest time improves its structure as well as its fertility. The billions of microorganisms present in organic mulches help improve the soil's capacity to retain moisture and oxygen.

Prevents Erosion and Controls Evaporation

• Mulch helps prevent topsoil erosion. Vegetable garden soil is susceptible to erosion from water, wind, excessive chemicals and the natural effects of plants growing. It takes nature up to 500 years to create once inch of topsoil, according to University of New Hampshire Extension. Home gardeners create topsoil by mulching and the continual addition of mature compost as a soil amendment. Mulch also controls moisture evaporation, reducing irrigation need by 50 percent. Stabilized soil moisture level improves vegetable quality and encourages growth of beneficial microorganisms.

How To Apply

• Mulch is applied after vegetable plants are 4 to 6 inches in height. Cultivate out weeds that have begun to grow. Spread a 4- to 6-inch layer of mulch evenly between the plants on the bare earth. Straw or hay mulches are kept at 6 to 8 inches deep, sawdust at 2 inches and grass clippings at 2 inches. A thicker grass clipping layer becomes matted, generates heat and begins to decompose. A 2- to 4-inch layer of ground corn cobs and hulls is covered with a layer of straw to prevent wind dispersion. Add more mulch as needed during the growing season to maintain an effective ground cover.