Gardeners have used black, clear, and infrared transmitting (IRT) plastic mulches to prevent weed growth, heat the soil, and increase the yields of their vegetable plants. Now there's a new mulch that's specifically designed to increase tomato yields.
Researchers at the USDA have shown that plastic mulch that reflects mostly red light increases tomato yields 12 to 20 percent compared to black plastic. Called "selective reflecting mulch," or SRM-Red, it works by reflecting far-red light up into the plant. Researchers theorize that the tomato plant responds as if it "thinks" it's being crowded and diverts more energy into the production of stems, leaves, and fruit.
Don't try to paint white mulch with red paint, because the red color has to be of a very exact intensity to produce the reported yields.
Preliminary results also indicate that SRM-Red may increase strawberry yields, too.
SRM-Red costs $10 for a 4-foot-wide roll that's 50 feet long.