Use care when cultivating around such plants as squash, cucumbers, melons and tomatoes. Mulches, both organic and synthetic, can be quite effective in reducing or eliminating annual weeds. Synthetic mulches, such as black plastic, are also effective for controlling perennial weeds. Unfortunately, most perennial weeds have enough food reserves to push through a layer of organic mulch. Mulches prevent light from reaching the soil surface and inhibit weed seed germination and growth.
Mulches also conserve moisture, prevent erosion, and reduce soil compaction.
Organic mulches also keep soil temperatures from rising to high levels. Apply organic mulches, such as grass clipping, straw, or shredded leaves, after the soil has had a chance to warm in the spring. Warm season crops require warm soils for good growth. Another advantage of organic mulches is they return valuable organic matter to the soil as well as small amounts of nutrients. A final method of weed control involves the use of herbicides.