To a plant, light is life.

No plant is naturally a houseplant. When your house is your garden you learn about light and about modifying indoor light to provide the energy with which plants convert natural elements into green growth and flowers. Very few indoor gardeners find too much light to be a problem. Quite the contrary. And we have learned that man-made sunlight (artificial light) can be used to supplement natural daylight or as the sole source of light for plant.

Two primary types of lighting are available for the indoor gardener - incandescent bulbs and fluorescent tubes. Fluorescent tubes have a higher light efficiency than incadescent bulbs; they give more even distribution of illumination.

With a comparatively simple addition of fluorescent lighting you can greatly increase your success and satisfaction in indoor gardening.

A 24-inch fluorescent fixture holding two 20-watt tubes is the minimum practical set-up. Tabletop units of this size are featured in seedmen's catalogs or are for sale at local garden centers. An electrical fixture of this size can be purchased at electric supply shops; with it, a handyman can make many adaptations for kitchen shelves, bookshelves, or elsewhere in the home for growing plants.

Comparable lighting for plants can be found by taking advantage of fluorescent lights already in place in kitchen or bathroom.

The 24-inch size is adequate for beginning but it limits the number and size of plants to be grown. Larger stationary or mobile units are available commercially which are adaptable for use in living quarters.

A more ambitious beginning in indoor light gardening can be made with the purchase of a fixture ordinarily referre to as a shop light. Hang such a fixture on chains form the ceiling at a height of about 12 inches above a work table or bench about 30 by 50 inches on which plants are to grow. The shop light is 48 inches long and holds two 40-watt fluorescent tubes. A pulley arrangement for raising and lowering the fixture is advantageous but not essential.

When the garden includes a number of plants of varying height, shorter plants can be raise closer to the light by setting them on upturned pots.

Ordinary cool white and warm white fluorescent tubes, one of each per fixture, are adequate for the all-purpose light garden. As you progress in interest and experience you will undoubtedly want to use tubes developed especially for plant grow, affording different qualities of light.

Light for 12 to 14 hours a day is sufficient for most flowering plant and many foliage plants do well with less. An automatic timer, costing about $10, is a great time saver for turning the lights on and off, and frees you for weekends away from or for other irregularities in your personal time schedule. They will not grow satisfactorily if exposed to continuous light.

A good temperature range is 70 to 75 degress in the daytime and 60 to 65 at night.

When growing plants under lights, your watering and fertilizing practices differ from those followed for plants grown in natural light. With the increased amount of light, the food-making processes of the plants increase and growth is accelerared. As a result the plant uses more food and more water. Some light gardeners follow a routine of constant feeding, that is, fertilizer at 1/4 to 1/2 the strength recommended by the manufacturer. Use lukewarm water at all times; keep the soil just moist.

With fluorescent light your plants will be sturdy and compact. Odd and new plants you haven't tried before can be added to your indoor garden.Seedings for next season's outdoor garden can be started early under lights.

The plants grown can be your familiar friends or challenging exotics. Start with plants you already have. Foliage plants do not require the additional light but will surge with new growth. Flowering plants have high light requirements and, in order to flower, must be in the good condition that can be achieved under lights.