Attach lights to the underside of shelves. Suspend lights from sturdy rope or chains so the lights can be raised or lowered, depending on the size of the plants they are illuminating.
Place starter pots containing seedlings on shelves. Place plants close together, but not touching, to encourage good air circulation and keep plants healthy.
Adjust the level of the light fixture so the light bulbs are only 3 to 4 inches above the tops of the seedlings. As the seedlings grow, raise the level of the light fixtures to maintain the same distance.
Keep lights on for 14 to 16 hours a day. An automatic electronic timer can help by turning on or off the lights even if you're not there.
Water your seedlings when needed, but do not saturate them. Overwatering can kill tender young plants.
When the weather warms enough outside, harden off your plants by bringing them outside and putting them in the shade. Start by placing them outside for a couple hours a day, and increase the time outside each day until plants are acclimated to the harsher outdoor conditions.