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best wavelength for growing weed

Best wavelength for growing weed

Many of the misconceptions about green light stem from how the human eye perceives green light. We easily perceive green light, but other colors, such as blue, are more difficult for us to see. Because so much of our environment (i.e., plant life) reflects green light, it’s adaptive for us to perceive green most readily.

But you won’t find green LED fixtures on the market or see green LEDs contained within a full-spectrum fixture. While green LEDs are useful for research, they’re not practical for commercial cultivation. Due to the constraints of manufacturing technology, green LEDs lack the electrical efficiency of other colors of LEDs. White LEDs, on the other hand, efficiently deliver green light and fill out other parts of the light spectrum too.

Or, feel free to check out the other two parts of this three-part series:

The Benefits of Green Light for Cannabis

Yet the laboratory is an isolated situation, and these studies purposefully create an experimental setting that would never occur in the real world. While informative, they don’t tell us everything we need to know about how living plants use sunlight. In the real world, the function of green light is more complex — and more important than once thought.

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.

In the canopy, green light that’s not reflected or absorbed by the upper leaves is transmitted, penetrating deeper into the lower leaves. And while it’s true that leaves reflect green light — and so appear green to our eyes — most of the green light is still used. Only 5-10% of green photons are lost to reflection; the rest are absorbed or transmitted.[2]

Green Light and LED Technology

Studies have shown again and again that cannabis plants use green light.[1] 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.

In this blog, we explore how green light affects cannabis and other plants, and how you can select lighting to maximize your growth.

Best wavelength for growing weed

However, similar to how we can’t actually eat food with our noses, plants can’t make energy from light using their photoreceptors.

Note: This article is aimed at intermediate to advanced cannabis growers looking for ways to improve their results.

A thermal camera works by showing warmer objects as lighter colors. So for example, the cold ground will appear dark, while a plant is a little warmer and will appear lighter. A human is warmer still and appears almost white on such a camera.

(Make sure to get a light made for this purpose, not just any green light will do!)