By NHGC Member Dorris Norris; Saltillo, MS
My husband built a 1- by 2-foot propagation box from scrap lumber. He added a clear plexiglass lid that can be lifted off. For a heating mat, we used a vinyl-covered waterbed heater that had its own thermostat. We placed the "heating mat" in the bottom of the box and covered it with a thin layer of builder's sand.
I start my seeds in 4-inch pots placed in a leakproof tray in the box so they can be watered from the bottom. When seedlings are about 1 inch tall, I move the pots to a sunny window. When the plants are large enough, I pot them up.