Get the Most From Vegetable Garden Mulches

Enlarge Image Image Gallery Mulches will conserve moisture, prevent weeds, reduce diseases and increase your yields.  ILLUSTRATION: ELAYNE SEARS

One of the hallmarks of any healthy organic garden is the effective use of mulches. Defined as materials used to cover the soil’s surface, mulches help control weeds, prevent disease, conserve moisture, maintain consistent soil temperatures, enrich the soil with organic matter and just make the garden look good. According to Texas A&M University, a well-mulched garden can yield 50 percent more vegetables than an unmulched garden space, thanks in part to mulches’ ability to reduce foliage and fruit diseases.

Most gardeners prefer biodegradable mulches, such as compost, grass clippings, leaves or straw, because they decompose into soil-building organic matter. In vegetable garden pathways or in orchards, sawdust and wood chips are hard to beat as perpetual mulches (see Use Wood Mulch to Build Great Garden Soil). Here we will focus on vegetable garden mulches used during the growing season, when their immediate purposes are to suppress weeds and diseases while moderating soil temperature and conserving moisture.

Mulching to Control Weeds

The longer a crop’s growing season, the more likely it is to benefit from mulching. In terms of weed control, the timing of the application of the mulch can be crucial to its effectiveness. For example, you could get good weed control at the start by mulching with newspaper and grass clippings over the area where squash or melons will run. But by the end of the season, the plot will be knee-deep in weeds that can’t be pulled without mangling the vines, so the best you could do at that point would be to cut back the weeds before they shed unwanted seeds. With peppers and tomatoes, however, it’s better to mulch later to get more sustained weed control. Weeding by hand for the first month or so, and mulching after weeds have been subdued, will usually keep weeds down for the entire summer.

To enhance weed control provided by organic mulches, many gardeners place newspaper beneath other organic mulches. Overlapped sheets of newspaper — about six sheets thick — will block light that could pass through thin layers of grass clippings or weathered leaves, resulting in far fewer weeds.

Homegrown Mulches

The best vegetable garden mulches are those that your property produces itself, such as grass clippings, leaves and compost made by combining kitchen and garden wastes. Grass clippings are particularly useful because they contain abundant nitrogen and other nutrients, which feed both soil life and plants. If used as mulch over fertile, organically enriched soil, a 2-inch blanket of fresh grass clippings can provide all the nutrients most crops need for the season.