The transmission of green into the lower canopy also decreases the senescence of the bottom leaves, and their sustained health lets them continue to help with photosynthesis. And green light drives photosynthesis directly too. In strong white light, green has been shown to drive photosynthesis more efficiently than red light. And the inclusion of 24% green light into a blue-red spectrum has been shown to enhance growth in lettuce. Without a doubt, the green light promotes growth.
Studies have shown again and again that cannabis plants use green light. But green light is different from red or blue. It behaves differently in the canopy, and different photoreceptors use it for photosynthesis — not just chlorophyll a and chlorophyll b.
Greenlight also signals plant morphology. It plays an important role in mediating a plant’s responses to blue light, and it influences leaf growth and early stem elongation. By sensing the ratio of light colors, plants can tell if they’re in shade or if they’re receiving direct light, and how to position their leaves to maximize light absorption throughout the day. That’s because green light penetrates leaves more easily than other colors. When plants sense a higher green-to-blue ratio, they assume they’re shaded by other plants, and they’re more likely to elongate their stems to compete.
The Benefits of Green Light for Cannabis
 Runkle, E. GrowingPlants with Green Light. Greenhouse Product News. 2017.
Greenlight — often neglected by lighting engineers — is a natural component of sunlight and an important part of any electrical light spectrum. But less extreme spectral tuning presents an opportunity for increased efficiency and control over plant traits. While it’s best to have all wavebands of the spectrum included in some proportion, increasing blue, red, or far-red light can elicit desirable characteristics in cannabis — like increased cannabinoids and terpenes.
Full-Spectrum LEDs or Blue-Red?
Greenlight is subject to the most misconceptions. While many growers believe cannabis plants don’t utilize green light for photosynthesis, they actually do, and green light is important for other processes as well.
So, when indoor growers are scouting their plants for pests, a fixture with the green light in the spectrum (i.e., a white-light spectrum) becomes an advantage. Under a blue-red light, recognizing pathogens like powdery mildew and fungus gnats can be next to impossible. When a spectrum includes even a small proportion of green, grow techs have a much easier time uncovering issues before they scale into major problems.
I personally grow plants from seed to harvest under HPS grow lights so plants grow taller, because the longer stems make plant training easier in my case. You can grow your cannabis plant from seed to harvest under any grow light as long as the light is bright enough!
You may be familiar with the term UV-A/UV-B when it comes to protecting your skin outdoors. We use sunscreen to protect our skin from UV rays from the sun in order to prevent skin damage. Too much UV exposure can give you sunburn now, and even carcinoma/melanoma in extreme cases!
(Make sure to get a light made for this purpose, not just any green light will do!)
Feminized cannabis seeds are important to cannabis cultivation because only female plants produce consumable flowers. LED grow light can boost sustainability and profits in cannabis.
Fail to manage the amount of exposure, you can find the following disadvantages:
Blue light for growing cannabis
Violet grow lights colors wavelength ranges from 380 to 450 nm. It is the bottom end light of the visual light spectrum. The range of violet light is considered as it improves the taste of flowers. In addition, it is considered to improve the potency and color of the plants. However, violet light cannot be considered as a major growth factor when compared to the red and blue light spectrum.
Red light whose wavelength ranges from 750 to 610 nm can be best viewed during sunrises and sunsets.
UVC (100- 280 nm)
Light is one of the most important factors in marijuana cultivation. Different spectrum colors have different roles in the development and growth of marijuana plants. Therefore, it is important to take care of the spectrum of grow light colors as they affect the growth of plants differently depending on environmental conditions. Normally, chlorophyll which converts light energy to chemical energy absorbs most of the light in red and blue light spectrums for photosynthesis. Therefore, both these lights are found at the top of the PAR range.