How Does Artificial Light Affect Plant Growth?

Artificial Light

How plant growth is affected by artificial light depends on the type of light that is being discussed. While all plants grow best in natural light, plants can an do grow and thrive under artificial lighting conditions. Overall, the best lighting choice should give off a high amount of blue, red and yellow light. Plants need the light in the blue spectrum to provide energy for photosynthesis. Light in the red spectrum encourages blooming, and yellow light is necessary for chlorophyll to be produced, which also aids in photosynthesis.

Grow lights, which combine these colors, are made specifically for growing plants indoors, and can be purchased at garden centers.

Household Lights

Incandescent lights, which are ordinary light bulbs found in most homes, create more heat than light, and are also high in red light. This type of light does not increase the growth rate, and the high heat output can burn the leaves of a plant.

Fluorescent lighting is better, but should still be supplemented with natural light. Fluorescent light tubes produce mostly blue light, along with some yellow, but they are very low in red light. Again, this means that the plants will not grow at a high rate. Because of this, fluorescent light should be supplemented with incandescent light if natural light is not available. The best fluorescent lighting for plants comes from tubes that are coated white. They should be placed near the plants, about only 6 to 12 inches above them. An incandescent lamp should be placed nearby as well, but farther away: about 2 feet from the plants.

Enough Light

Although the way in which artificial light affects plant growth varies by the type of light, the amount of artificial light is just as important. Artificial lights are not effective in encouraging plant growth if they are on for a limited number of hours per day. While plants only need 6 to 8 hours per day of natural light, this amount of artificial light will cause a plant to die. For a plant to thrive, it needs at least 12 hours of artificial light per day and possibly more, depending on the plant and the type of light.

Resources

• More about growing plants under artificial light