When starting seeds [1], soil temperature is very important. Often it is difficult to find a suitable place in our homes where the temperature is ideal for germinating seeds. But with just a few common household items, you can easily put together a hot box that can regulate temperature.

You will need an inexpensive Styrofoam cooler, cookie sheet, black paint, porcelain light fixture including the junction box, electrical cord, a 25 watt light bulb, and a dimmer switch.

Begin by painting the cookie sheet black [2]. The dark color helps the cookie sheet absorb heat from the light. Next, wire the dimmer switch into the electrical cord of the light fixture. To assemble the unit, position the light fixture firmly in the bottom of the cooler [3] so that it will not tip over. You can make a slit in the cooler to accommodate the cord. Cover the cooler with the cookie sheet so it just fits over the opening.

Place the seeded containers on the cookie sheet and cover them to conserve moisture For covers, you could use the top of the cooler, Saran wrap, or a sheet of glass. Monitor the temperature of the soil with a thermometer and adjust it by turning the intensity of the light up or down with the dimmer switch. As soon as the seeds have germinated, they should be removed from the hot box and placed under lights to continue growing.