How Different Colors of Light Affect Plant Growth
The growth of a plant might seem like a simple and straightforward process. The plant needs to be watered, the soil needs to have certain nutrients, and it needs to be in an environment where it receives light for a certain amount of time. Yet not many know how the latter can have a big impact in the development of a plant… until now.In this post, I'll explain how different color lights affect plant growth, jumping into detail on the characteristics that light possess, and how you can use different colored LED grow lights to change the properties of plants and make plants grow faster
What Exactly is Visible Light?
A crucial component in the growth of a plant besides water and oxygen, is sunlight. By receiving it, a plant is able to convert sunlight into edible food that it can use. This process is called photosynthesis. Water, oxygen, and sunlight make the holy trinity for plants.Visible light as we perceive it behaves as a wave. As such, it displays different properties depending on its wavelength. For example, a source of light with a wavelength of around 650 nm will be detected as having a red color.
Multiple studies have been conducted on how different colors of lights can have varying effects on the growth of a plant.
Thanks to the recent developments in LED (light emitting diode) grow light technology, specific light wavelengths can now be isolated in order to control the different physical properties that a plant displays as it develops throughout its life cycle. These properties include, but are not limited to, height, weight, color, and texture, as well as the chemical composure of the plant itself.
As a plant grows, you can use LED grow lights to manipulate these physical properties depending on the plant characteristics that you desire.
The Effects of Each Color of Light
In the following paragraphs, I explain what each light color does, and the effects that adding or removing them will have. But first, here is a quick summary, with extended information following:
Ultraviolet - No exposure produces better growth
Violet - Enhances the color, taste, and aroma of plants
Blue - Increases the growth rate of plants
Green - Enhances chlorophyll production and is used as a pigment for proper plant viewing
Yellow - Plants exhibit less growth compared to blue and red light
Red - When combined with blue light it yields more leaves and crops, depending on what is being grown
Far Red - Speeds up the Phytochrome conversion which reduces the time a plant takes to go into a night-time state. This allows the plant to produce a greater yield
Ultraviolet (20nm to 380 nm)
Being exposed to UV light for a long period of time has harmful effects on humans. Likewise, exposure for a long time to this type of light will damage the plants that you are growing.A study conducted demonstrated that plants raised without exposure to UV light exhibited enhanced growth.
Violet (380 nm to 445 nm)
On the other hand, studies have shown that when a plant receives visible violet light, the color, taste, and aroma of the plant are enhanced.Additionally, the plant’s antioxidants are able to perform their functions more efficiently, which prevents the cells in the plant from being damaged.
Blue (450 nm to 495 nm)
Blue light has one of the largest effects on the development of a plant. Multiple studies have shown that exposing a plant to this color influences the formation of chlorophyll, which enables the plant to intake more energy from the sun. It also controls a plant’s cellular respiration and lessens water loss through evaporation during hot and dry conditions.
Blue light also has an effect on photosynthesis, and more exposure to this light can increase a plant’s growth and maturity rates. This process is called photomorphogenesis.
Overall, blue light has an influence over multiple functions in a plant’s life, and is a crucial color to have in your own grow room or grow box in order to ensure the most optimal growth.
Green (495 nm to 570 nm)
Most of the plants that we see around us possess a green color. This is due to the fact that they absorb all of the colors in the light spectrum (blue, red, violet, etc) but reflect the green one. As such, only the green light is bounced back to our eyes.
Even with the relatively low amount absorbed compared to the other colors, a study found that green light enhances the production of chlorophyll which helps with photosynthesis while giving the plants a greener color.
Overall, adding the green color to your plants does not have much effect in their life process compared to other light colors such as blue. Employing this type of light would be as a pigment for proper viewing of your plants in the grow room or grow box, but not necessary for the growth of the plant itself.