Give your plants a head start with an indoor greenhouse. Plant seedlings in your home while it's still cold out, and within a few weeks they'll be large enough to transport outside. The key to a successful greenhouse is making sure your plants have enough light, moisture and warmth.
Set up a shelving unit in a warm (but not hot) area in your home. Ensure that the shelving unit has enough open space between shelves so that you will be able to attach a light to the top of one shelf and still allow 3- to 4 inches between the light and the tops of plants. The unit should be sturdy.
Suspend one or two shop lights with fluorescent bulbs under each shelf so that the light will shine on the entire area of the shelf below.
Attach lights to timer on a central power strip and program the lights to be on from 10- to 18 hours a day, depending on the types of lights you have. Follow the light manufacturers instructions for greenhouse lighting.
Lie trays down on the shelves to catch any extra water so that no drips can fall on the lights below. Set the covered seed flats on the trays. Leave the top shelf bare.
Hang a sheet of plastic over the entire shelving unit so that moisture will be kept in. Don't secure it from the bottom, as you will still want to be able to get in and water the plants. Make sure the sheeting is not touching any of the lights.