Grow lights allow you to start plants indoors even if you do not have a well-lit window to place the seedlings in. Some lower-light plants, such as leaf lettuce and spinach, can be grown to maturity indoors under lights if you don't have a suitable garden space. Grow lights are available in adjustable stand fixtures or in standard fluorescent fixtures that you affix to the wall, under a cabinet or hang from the ceiling. Setting the lights up so they provide the maximum benefit to your plant is vital for any grow light system to work.
Place the grow light fluorescent tubes into your fixture. Use either lights labeled as grow lights or substitute one warm white and one cool white fluorescent tube in a dual-tube fixture.
Adjust a stand light fixture so it sits 4 to 6 inches above the top of the plants, moving the fluorescent tubes either up or down in the fixture arm brackets. For mounted, non-adjustable lights, place a stack of newspaper or wooden planks under the plant pots to elevate them to the proper distance from the grow light. Adjust the length of the chain to the correct height if you have a hanging fixture. The chain attaches to the ends of the fixture.
Plug the grow lights into an automatic timer, then plug the timer into a wall. Set the timer so it comes on for approximately 14 to 16 hours each day, then automatically turns off for eight to 10 hours. Most plants require twice as much artificial light as they do natural sunlight.
Adjust the height of the lights as the plants grow to maintain the 4 to 6 inch height difference between the lights and the plants. Adjust lights on their stands or chains or remove newspapers or planks from the stack to lower the plant pots.