Experienced gardeners know that the use of grow lights makes all the difference in the world for plants grown indoors. Their primary use is in starting seedlings to be set outside when the weather allows. Grow lights can also be used to create an indoor garden of flowering plants.

A plant's life cycle is very closely linked to the circadian rhythm, the alternation of light and dark. Amazing as it may seem, even seeds and tubers buried under the soil can sense the lengthening of days in the spring. This signals them to germinate or start putting forth new growth. You can even see this happening in your kitchen vegetables: carrots in the fridge will sprout green leaves and onions in a dark cupboard will put out shoots.

There are two basic types of grow lights for home use. Regular fluorescent lights can be used, as long as they are kept within four inches of the tops of the plants. Most grow light stands are easily adjustable so you can maintain that range. Using metal halide lights will result in plants with a more compact growth habit, similar to how they would look if they were grown outdoors.

Remember that plants need periods of dark as well as light. Many flowering houseplants, especially those that are grown for seasonal bloom, require specific periods of light and dark in order to set buds. These include azaleas and gardenias, Christmas cactus, Easter lilies, poinsettias and many spring-flowering bulbs.