Light is one of the four primary factors necessary for maintaining the essential processes and reactions needed for plant development. If you are a gardener who is enthusiastic about growing some leafy greens or some pulpy tomatoes, you will surely be curious about how does the color of light affect plant growth.
If we are to be a little more specific, we can observe that not only the presence of the light, even the varying colors of the light itself can have a significant influence on how fast or slow your crops are growing.
This post is specially written and articulated for eager individuals who are keen on understanding how different colors of light can have different implications on plant development.
We have also given an overview of how light intensity can have an impact on plant growth cycle and how artificial light can act as a viable alternative in providing a diverse spectrum of light if natural sunlight is not available.
So, anticipate no longer and read ahead to have quick answers to all your questions.
How Does Light Color Affect Plant Growth?
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.
Under What Color Light Do Plants Grow Best?
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 one 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 affect 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 its 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.
What Happens If There Is Too Much Light?
So, you already know how does colored light affect plant growth, right? Excessive light should be avoided to ensure active plant growth. In fact, too much light can cause the organs of the plants to become dysfunctional, eventually leading to the death of the plant.
While plants tend to grow better as the light intensity is increased, a number of problems arise when the light becomes excessive:
- Chlorophyll content in the leaves is reduced. As a lower amount of chlorophyll leads to a lower rate of photosynthesis, the growth of the plants becomes restricted, leading to unhealthy production of plant products.
- As temperature rises with increasing intensity of light, plants undergo a faster rate of transpiration, which leads to an increased amount of water loss. Leaves will lose turbidity and start to wither, losing the capacity to photosynthesize over time.
- Enzymes present within the plants become inactive due to excessive light, and plants are unable to convert sugar to starch. This limits the food storage within, limiting the growth rate of the plants.
What Happens If There Is Too Little Light?
Extremities are never good. While too much light can cause detrimental impacts on plant growth, too little light can also significantly hamper the healthy activities by plants.
In general, lower light intensity slows down plant metabolism, limiting all chemical and physical events within the plant body, which can lead to several issues:
- In the dark, plants are unable to photosynthesize due to the unavailability of blue light, which leads to a lack of food production and a reduction in chlorophyll. Eventually, plants will lose all their chlorophyll and green pigment, and slowly die off.
- Etiolation is a condition where the stems of the plants become elongated and stretchy due to the absence of light, and this in turn makes the stem very weak and decreases the size of leaves.
- Enzyme activity will start to fall with lower light intensity. As enzymes play essential roles in maintaining the primary metabolic reaction within plants, decreasing the rate of enzyme activity will drastically affect plant growth.
While different colors of light and their varying intensity are two fundamental aspects of plant development, the type of light present is also an important factor to address. There are two types of light: Natural sunlight and artificial light. Let’s have a quick look into these.
- Natural sunlight
Natural sunlight comes with an entire spectrum of colors, providing all ranges of light starting from shades of violet to shades of red. It is free and in infinite amount, making it the most viable option for plants to absorb more energy and grow at faster rates.
Unfortunately, not all plants nor all regions around the world have equal access to sunlight due to seasonal, geographical, and climatic variability, thus the plant growth rate becomes restricted or stunted in such cases. But luckily, due to technological advancements, we are able to provide rich spectrums of light to all parts of the world through the use of artificial lighting.
- Artificial light
Fluorescent tubes, incandescent bulbs, and Light Emitting Diodes (LEDs) are a few of the most common sources of human-made light utilized by millions of people around the world. Out of these, LED lights act as the best option to provide artificial lighting to plants for their growth and development, providing a full spectrum of light for all growth stages.
Over the last few years, gardeners are largely benefiting from LED grow lights. Due to portability and complete control over the color or duration of light shone over the plants, these lights have played a significant role in the change of traditional gardening.
One popular example of such cases is a indoor grow tent.
Grow tents have become a convenient way of producing plant products indoor, more and more people are opting for this alternative compared to growing plants outdoors.
LED lights are installed within the tents, which provides them with all colors of light, and different shades of light can be chosen at different plant growth stages, leading to healthier and efficient growth of plants.
These lights themselves vary due to several aspects such as the type of the plant, number of plants, and size of the grow tent, among many others. For instance, the LED light for 4×4 grow tent during a particular growth phase of the plant will surely differ from the LED needed for a 5×5 grow tent due to size variability.
Thus, artificial lights can surely act as a feasible substitute for light to ensure productive plant growth.
Hopefully, you are no longer wondering how does the color of light affect plant growth. Light plays a vital role in plant growth, and the absence of this essential factor will have a large number of negative impacts.
The color of light required during different phases of the growth cycle is an important aspect to address in order to attain the highest level of yield.
While violet, blue and red lights are a must for the plants, shades of yellow and green are not as effective.
Light intensity and the type of light used can also lead to variable yield. Thus, it is crucial to find the perfect balance in all these facets if we are to achieve adequate growth from our crops. Here is a video demo on how lights can impact your indoor plants.