Using Grow Lights To Vegetable Plants

When plants are not getting enough lights, what’s the indicated sign? Yellow leaves and weak, spindly growth indicate that phenomenon. Plant growth is largely determined by light quality, intensity and length of exposure. The sun is the best provider of all aspects of light. However， you have to emulate the conditions that the sun provides by using grow lights when growing vegetable plants indoors.

Light Quality 
Quality of light means that the wavelength or color of light. Blue light is needed for growing leaves. Red light and blue light together grow flowers. Full-spectrum fluorescent bulbs (grow lights) emit high levels of both red and blue light and instead of the sun. High intensity discharge lamps (HIDS) produce twice the light but are expensive and not necessary for home gardeners.
 
Light Intensity
Summer sunshine provides the highest intensity of light. To replicate this light indoors, suspend the grow lights directly above the plants. The light must be close but not touching the leaves, one to two inches. As the plants grow, raise the lights accordingly. Placing the lights further away from the plants decreases light intensity. The plants will grow spindly and not be as healthy.

Light Duration 
Vegetable plants need a period of darkness to convert their photosynthesized energy into food. Darkness is also required for the plant to produce flower buds. Sunlight is required for photosynthesis and to ripen the plant's fruit. Vegetable plants need varying amounts of light depending on the species. For best results, put your grow lights on a timer set to 12 hours of darkness and 12 hours of light.

Special Considerations of Fluorescent Bulbs 
Fluorescent bulbs have the most light intensity at their center. Rotate the plants daily so the ones at the end have a turn under the middle of the bulb where the light intensity is the strongest. Be sure to discard the light bulbs after every season because the amount of light they produce drops drastically after a year.