How Does The Color Of Light Affect Plant Growth

The growth of a plant might seem like a simple and straightforward process.

While keeping the plant alive can be easy, getting it to thrive can take a bit more work. You want your plant to thrive as it will yield more cannabis if it is healthy. 

The plant needs water, the plant needs certain nutrients- not too much or too little, and it needs to be in an environment where it receives light for a certain amount of time. 

However, not many know how much light can have an impact on the development of a plant… until now. 

In this post, We will explain how different color lights affect plant growth, jumping into detail on the characteristics that light possesses, and how you can use different colored LED grow lights or full spectrum white led grow light to change the properties of plants and make plants grow faster and stronger.

Full spectrum of light

A crucial component in the growth of a plant besides water and oxygen, is light. By receiving it, a plant is able to convert sunlight into nutrients that it can use. This process is called photosynthesis. Water, oxygen, and sunlight make the holy trinity for plants. 

Process of photosynthesis

Visible light is part of the electromagnetic spectrum. Visible light is a tiny portion of that spectrum. 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.

Cannabis plants are very sensitive to light. Beyond needing the right amount of the right spectrum of light, the type of light and spectrum vary depending on the stage of growth your plant is in. For example, when your plant is in its vegetative stage of growth, blue light is the most beneficial as it promotes vegetative growth. 

Chlorophyll is the green pigment in plants responsible for conducting photosynthesis. There are two different types of chlorophyll, chlorophyll A and chlorophyll B. Chlorophyll A is responsible for the majority of photosynthesis and absorbs red and orange light. Chlorophyll B is responsible for increasing the amount of light spectrums a plant can use for energy and absorbs blue- violet light.  Also uv lights for plants is important.

Multiple studies have been conducted on how different colors of lights can have varying effects on the growth of a plant. 

Natural sunlight provides all spectrums of visible light. In summer, there are more blue-green wavelengths, which help plants grow big. In the late summer and fall, when the sun is lower on the horizon in the evening, there are more orange-red wavelengths. These wavelengths help plants grow flowers and reproduce before its winter. 

Light has a significant role to play during the various growth phases of crops and plants. In fact, without light, the majority of the flora that we see around us would not even exist!

So, what is the science behind this?

Plants are beings that produce their food within their leaves using photosynthesis, and one of the major factors, in order to do so, is the presence of light.

A green pigment called chlorophyll traps in the energy from the light, and the plants will further go through a number of processes and utilize that light into making food for themselves.

As the plants produce more food, they grow bigger in size and provide more plant products. But do all types and colors of light produce the same amount of yield? We will discuss that in the next few sections.

Before we know the answer, we need how does colored light affect plant growth or not? Well, you will know shortly.

While plants will absorb a certain amount of energy from all colors of light, the absorption rate will greatly vary with the different colors, and so will the growth of the plants. More absorption equals more growth!

The reason there is a variation is due to the different wavelengths of different colors of light. Depending on how long or short the wavelengths are, the plants will trap in the energy accordingly.

These wavelengths differ over a range of different colors present in the color spectrum. At one end of the spectrum, there are shades of dark purples and blues, and on the other side, we will observe that there are shades of oranges and reds present.

Let’s have a look at how the plants absorb these different colors and how they affect their growth.

• Violet or Purple light

Light of violet or purple shades have the shortest wavelength compared to all others, and thus they have the highest energy as well.

Plants readily absorb a high amount of these lights during photosynthesis, and these shades play a major role during the growth of plants in the vegetative stage.

Violet lights facilitate the development and growth of the leafy parts of the plants, and they also produce fruits and vegetables that are better in taste and smell.

Furthermore, plants produce more antioxidants in their body in the presence of these lights.

All in all, purple or violet lights are a treat for our green friends in case you are wondering how does light affect plant growth!

• Blue light

Blue lights are also happily taken in by plants due to their short wavelengths and high energy potential.

These lights are vital during the initial phases of plant growth as they allow the plants to produce more chlorophyll in their leaves, which facilitates them to absorb more light afterward.

During seeding, plants need to take in a large amount of blue light to ensure healthy stems and roots, as well as faster growth of the leafy vegetation.

In fact, without a healthy and sufficient dose of blue light, the seedlings may never sprout out of the ground altogether.

• Green light

While plants do absorb a limited amount of green light, they are not big fans of it. As most parts of plants are already green due to the presence of chlorophyll, green lights are least absorbed by plants and thus are one of the least effective for plant growth.

Greenlight has mostly reflected away from the plant surface, making the plant look greener than it is. In conclusion, its best if green lights are not directed towards plants as they do not benefit the plants much in any aspect.

• Red light

You will be amazed knowing how does red light affects plant growth!

Red lights have the longest wavelength in the color spectrum, and thus they have the least energy as well. Shades of red and oranges play a significant part in plant growth, and their presence is a must during the blooming and flowering stages of plants.

Moreover, red lights also prevent the breakdown of chlorophyll, which allows the plants to absorb more light and retain more energy for further growth.

Although these lights are not required during the initial phases of plants’ growth cycle, if red and blue lights are combined, they create a considerable impact in producing larger and healthier leaves. Thus, red lights are a big “yes” by plants, well… only if they could talk!

• How Does Yellow Light Affect Plant Growth?

Yellow light barely has any role to play during plant growth. As a matter of fact, scientists argue that removing yellow light can actually produce healthier plants compared to plants who are exposed to it.

This light is considered to be the least beneficial for any crops, and any substantial contribution of this light towards plant growth is yet to be discovered.

Now that you have an understanding about which color of light will be the most or least relevant towards plant growth, it is also crucial for you to know how light intensity plays a role in plant development and yield.

All plants have an optimum and peak level of light intensity where they flourish the most, and the growth rate is the highest.

Although different species of plants have different peaks, straying away from that optimum intensity will have a negative effect on plant growth.

ECO Farm ECOY 600W Movable LED Grow Light Bar with Samsung LM301H Chip

 Pros:

• Promotes maximum yield using less energy


• Provides a complete and customizable dual-light spectrum


• Secondary focusing lenses reinforces its finely tuned spectrum

Cons:

• The fans can be a little noisy


• The light only covers what’s directly underneath it

Plants react differently to different colors of light.

Everyone knows plants are food factories, and most are aware that their energy source is light. This transformation of light into food is called photosynthesis. What may be news to you, however, is that the color of the light has a measurable impact on the amount of energy a plant absorbs. The reason for this is the colors in light have different wavelengths and those wavelengths, Infrared Light depending on whether they are short or long, provide different levels of energy.

The highest energy light is at the purple or violet end of the color light spectrum. Purple and violet lights have short wavelengths and thus lots of energy. At the other end of the spectrum, you will find red light which has long wavelengths and emits lower energy.

Regardless of whether the color of the light is red or purple the plant will absorb some amount of energy from the light it is receiving. Green light is the least effective for plants because they are themselves green due to the pigment Chlorophyll.

Different color light helps plants achieve different goals as well. Blue light, for example, helps encourage vegetative leaf growth. Red light, when combined with blue, allows plants to flower. Cool fluorescent light is great for cultivating plant growth indoors.

Knowing that different colors of light can affect what a plant does is important in a world that depends on plants for food. Advanced LED technology is now making it possible to control the kinds of colored light we provide plants in controlled environments.

We can now design lighting to encourage flowering or to produce higher fruit yields for example. Many plant functions can be enhanced and promoted just by knowing what light colors they react and respond to.

For a hungry world just waking up to the effects of Global Warming, this is critical. It will allow us to provide environmentally friendly alternatives to help improve crop quality and growth without having to resort to powerful fertilizers and genetically modified food.