Hydrofarm Heat Mats speed seed germination and stimulate root growth by keeping soil at about 70º F. These Heat Mats are engineered for better performance and greater durability than most of the similar mats on the market today. We use stronger heating wire and thicker multi-layer construction offering more uniform heat and the durability to withstand rugged greenhouse environments. The Hydro Farm Seedling Heat Sheet gently warms the root area up to 20 degrees Fahrenheit (11 Celsius) over the ambient air temperature. This improves germination and will increase the success of seedlings , cuttings and clones. Easy to use instructions printed right on the mat, along with some propagation guides for many popular varieties of plants. For precise temperature control, check out our Heat Sheet Digital Controller.