Most LED grow lights emit what we see as white light which like sunlight, is actually all colors of the spectrum hence, full spectrum. While plants do well when exposed to full spectrum lighting, their photoreceptors are especially responsive to a specific group of colored lighting. Here are the three essential colors your plants use to photosynthesize and grow to their fullest.
Warm White (Red) Light
Plants use red light as their primary driver for stem growth, leaf expansion, and overall plant height during the flowering stage. Ranging from 2000K-3000K and 640-680 nm, red light emitting over your plants will promote greater yield production and a greater quality yield. This is because it signals to your plant that there are no other plants over it to stop it from continuously growing. The warm white lighting also encourages fruit and chlorophyll production, used to extend light cycles of long-day plants or shorten that of short-day plants.
Cool White (Blue) Light
Whereas red light facilitates plant growth during flowering, blue light can stunt it, especially when plants are overexposed to it. Thus, it is usually mixed with other colored lights so that this stunting is mitigated. Instead, blue light ranging from 5000K-6000K and 400-500 nm is best used in the seedling and vegetative stages. It promotes leaf growth and stimulates secondary pigment production, enhancing your plant’s color and fragrance.
Green lights find their use during dark cycles since it doesn’t trigger photosynthesis or photoperiod hormones. Because chlorophyll in plants do not absorb much green light, it is able to penetrate deeper below your plant’s canopy and reach photoreceptors that other color lights cannot. The result is a more lush plant with verdant leaves on top of a fully developed canopy.