Back by popular demand is the highly reflective 1mil. smooth mulch. USDA and university researchers have found that red plastic mulch enhances the growth and yield of several vegetable crops, including tomatoes. The color of the mulch changes the intensity of certain wavelengths of light, and the modified light increases plant growth and yields. Trials have shown tomato yields to be as much as 20% higher using SRM-Red mulch than using black plastic mulch. Results vary from year to year depending on available light.