Wind injures tender vegetables and increases water evaporation from the soil, creating a hard crust. Late spring frosts and hail can kill plants, leading to expensive replanting and delays in crop maturity. Plastic mulches warm the soil and encourage early root production.
Clear plastic heats the soil but encourages weed growth.
Black plastic provides better weed control and moderate soil heating. An older technique for protecting vegetables is placing clear plastic tunnels over the plants. Although more expensive than plastic tunnels, fabric row covers provide weather protection and better ventilation, Dickerson said. Row covers can be floated over the crop or supported with wire hoops. Row covers work best in combination with a black plastic mulch.