This seedling heat mat is an excellent way to improve both the speed and rate of germination of your seedlings. This waterproof heat mat increases the soil temperatures 10-20 degrees above ambient room temperatures, making your seeds happy and warm. This mat is just the right size for 4 Jiffy greenhouse trays.
I really saw a huge difference in speed of germinations. Instead of having a slow time with all the plants sprouting over a long period of time, I had everything come up at the same time, and very quickly. If you are serious about starting your own tomatoes and peppers, this is really a must have. My only suggestion is to protect the surface you put it on. The excess heat can warp surfaces, so putting it on a piece of plywood or some styrofoam insulation helps a lot.