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best light spectrum for growing weed

Best light spectrum for growing weed

The blue light spectrum is very important for marijuana plant growth. It is mainly responsible for increasing plant quality. During the vegetative stage of growing marijuana, you should aim for growing leaves as many as possible. The blue grow lights colors wavelength is from 450 to 490 nm. Indoor growers use T5 or T8 lighting fixtures, CFLs (compact fluorescent lamps), or metal halide bulbs that have a blue band of light. They use these for the first few weeks to achieve desired goals. When marijuana plants grow outdoors the angle of the sun during spring allows blue light energy which is abundant in this season to penetrate the leaves. Therefore, this blue light signals the plants to grow healthy and large leaves and to become strong. The plants that are deficient in blue light generally turn out yellow or pale and are weak and flopping. Blue light is essential for young plants and seedlings in vegetative stages to properly grow roots and stems.

The disadvantages of UV light for marijuana plants

Ultraviolet or UV light having a wavelength that ranges between 10 to 400 nm is known for being harmful to human skin when exposed to it. Ultraviolet light in larger amounts can also harm plants. It is not visible to the naked eye and sits at the lowest end of the light spectrum. However, just because it is not visible, does not mean it is not useful to the plants. A small number of UV rays can be beneficial to the aroma, flavor, potency, and growth of marijuana plants.

Green light for growing cannabis

In this article, you will learn about color spectrums that are needed for marijuana growth. Also, how grow lights colors affect marijuana growth.

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.

UVC (100- 280 nm)

Red light whose wavelength ranges from 750 to 610 nm can be best viewed during sunrises and sunsets.

98% of the UV light that is reaching Earth contains UVA, which makes it an important part of the natural environment. If you are growing marijuana outdoors, you do have to worry about boosting UVA levels as your plants naturally receive plenty. UVA may help boost the THC level for indoor growth when you increase the exposure during the flowering period. However, for humans being exposed to UVA for long intervals can increase the risk of skin cancer. Therefore, you should make sure to protect yourself with sunscreen.

Best light spectrum for growing weed

In addition to the effects on how a plant grows, green light is what make plants appear natural and green to us. Plants under LED grow lights with just red and blue light tend to look dark or purple similar to how plants look very yellow/gold under a HPS. By adding a little bit of green we can actually see the natural color of leaves, which makes it a lot easier to spot problems!

But like the other spectrums, plants seem to want just the right amount of green light for the best growth, not too much or not too little. After many experiments with green light, the NASA Biological Sciences research group has reported that light sources consisting of primarily green will cause plants to grow slower. However, combinations of red and blue including up to 24% green actually enhanced growth for some plants over purely red and blue light.

Note: I’ve used all types of grow lights during all stages of growing marijuana, and even when you’re not using the “right” color spectrum, you will still produce potent buds with any strong grow light! I’ve even used “bright white” CFL grow lights (which have high levels of green), and you may be surprised to learn that these work great for growing weed, too!

Once the seed reaches the surface and gets exposed to blue light, it stops acting like a root and starts acting more like a seedling, opening its leaves and growing towards the closest source of blue light. If it doesn’t get a good amount of blue light at the surface, it continues to grow its main stem longer and longer without making any leaves, acting more like a root than a plant because it still “thinks” it’s underground, or at least hidden from the sun.

What to focus on for best results when it comes to quality of light: