Good Indoor Fluorescent Light for Plants

Plant Light Requirements

• Sunlight is the best light for plants. It is high-intensity light that contains all light wavelengths. Plants don't use most of the light wavelengths, but they do need large amounts of blue and red light for growth and photosynthesis and infrared light for flower and fruit stimulation. Artificial light in lower intensities than that found in sunlight can provide these wavelengths. Plants that grow tall and spindly or have unnaturally light green or yellow leaves need more light intensity.

Light Intensity

• Light intensity increases as you get closer to the light source. The solution to the low-intensity light fluorescent bulbs produce is to place the plants close to the light source. It is important to keep the plants far enough away to prevent burning, while still maintaining light intensity. In general, place plants approximately 6 inches from fluorescent bulbs. You will have to keep a close eye on the plants as they grow. If you notice the leaves browning or drying, move the plants farther away. Keep the lights on for 16 hours every day.

Wavelengths

• Light wavelengths vary with different fluorescent bulbs. The cool-light bulbs produce light in the blue wavelengths that plants need in quantity. The warm-light bulbs produce the red wavelengths. Grow lights produce a mix of the blue and red wavelengths. By mixing cool and warm wavelength bulbs, you can provide the needed wavelengths without paying for expensive grow lights. Use one warm-light bulb for every three or four cool-light bulbs. You can put them in the same fluorescent fixtures with no problems.

Suitable Plants

• In general, plants that need low light levels do best under fluorescent bulbs. Medium- and high-light plants can be grown, but a location with some natural sunlight is best, supplementing the light with fluorescent bulbs. Fluorescent lights are also good for starting seedlings for the garden. Lettuces and other green plants do well.