How does the color of grow light affect plant growth

How does the color of grow light affect plant growth

Photosynthesis is the process that plants go through to change light, water and carbon dioxide into glucose and oxygen. Glucose is a type of sugar and is used as a food for the plants. The byproduct of photosynthesis is oxygen.

Photosynthesis cannot take place without chlorophyll. Chlorophyll is what makes plants green and allows plants absorb light energy and turn it into food. Since chlorophyll is green, colors on the opposite side of the color spectrum are most efficient for plant growth including red and blue.

Light is a type of energy and it varies based on the wavelength of the color.

Ultraviolet has the shortest wavelength so it has a higher energy, this is followed by violet, blue, green, yellow, and lastly red which has the longest wavelength and is least energetic. This is important when considering which light to use for plant growth. Since UV light is so energetic, it's actually harmful to plants. And since red light is less energetic, it is less effective when used by itself.

All this is important to understand how light affect plants. Without the proper energy from light, plants would not be able to go through photosynthesis and produce food to sustain the plants.

Which Color Of The Light Spectrum Are Most Important For Plant Growth?

Plants grow, that is a given. Have you ever thought about the light that makes the plant grow? The light spectrum that those plants use is completely different than what you think.

You think of the sun as yellow, it is much more than that. How do we know this?

A rainbow forms when sunlight enters droplets of water. When done at a specific angle the droplet separates the light into many different colors, and you see the entire visible light spectrum. Those visible colors being red, orange, yellow, green, blue, indigo, and violet.

The Effects of Each Color of Light Blue Light Blue light is essential at the beginning of a plant’s growth cycle as this is the type of light that plants first absorb to help with chlorophyll production. Your plants need lots of blue light during the seeding process and right through the first part of their growth cycle to ensure healthy roots, strong stems, and healthy leaves as well. Without blue light your plants will never get out of the

ground, so any lighting system that you put together should include a healthy dose of exposure to this type of light.

Purple Light As we move up the light spectrum you move into purple light, and while this may not be familiar to most of us it can certainly help your plants to grow.

Purple light has a much shorter wavelength than red light and it can be just as effective in helping your plants through the vegetative growth process as blue light. This type of light is very energetic and that energy can be used by your plants, although it won’t be overly effective by itself.

Green Light While there has been some debate recently on the merits of green light during a plant’s growth cycle there’s a good reason plants normally have green leaves – that’s because they are least effective at absorbing this type of light. In general, plants use less of the green light they absorb than any other part of the spectrum and that’s why your plants appear green, but that doesn’t mean they don’t use any green light at all during the photosynthesis process. Some green light is retained by your plants for photosynthesis; leaving this part of the spectrum out altogether can negatively affect the growth of the plants.

Yellow or White Light Yellow light isn’t the most effective part of the spectrum for plant growth, but it is still present in sunlight and so it’s still important to ask the question of how plants use yellow light during the process of photosynthesis. It turns out there are a lot of people that are convinced it doesn’t do much at all and that by removing yellow light altogether from your indoor grow lights you can actually produce plants that are healthier than plants grown outdoors.

This is certainly debatable, but what is certain is that yellow light is one of the least effective parts of the spectrum during your plants’ growth cycle.

It might seem intuitive to assume that yellow and white light are close to each other on the spectrum, but that’s not the case at all. White light is actually made by combining other colors on the spectrum such as red, green, and blue. Therefore white light will actually be much more beneficial for the photosynthesis process than yellow light.

Red Light Red light has longer wavelengths than blue light and is therefore a lot less energetic. It’s important that your plants are exposed to red light during the blooming or flowering stages, but this type of light is not essential during the vegetative stage of your plants growth – in fact if you were to use only red light during the initial stages of the plants growth cycle your results would

not be very positive at all. It’s best to use red light towards the end of the growth cycle in combination with some blue light as well.

A Full Spectrum of Light For the healthiest plants you really need to include light from right across the color spectrum. While it’s true that certain types of light may be more effective at different stages of the growth cycle, your plants still need light from across the spectrum at any stage of their growth. If you concentrate your light too much on one end of the spectrum you probably won’t like the results.

Focused Intensity If you expose your plants to higher concentrations of certain types of light at different ends of the growth process you’re likely to get the best results. As we’ve mentioned elsewhere on this site and touched on in this article as well, blue light is very effective during the vegetative stage of the plants growth cycle, but you should introduce more red light during the blooming stage.

Different Light at Different Stages Understanding how the color spectrum affects plant growth may seem a little overwhelming at first, but once you get the basics down it’s pretty straightforward. Essentially, there are different types of light that are more important at different times during the plants growth cycle. In an indoor grow operation you can manipulate the type of light your plants are exposed to in order to optimize their growth; just don’t eliminate other light altogether at any stage and you should be just fine.

So What is the Best Color for Plants?

Out of all the colors mentioned above, the most crucial ones in the development of your plant are red and blue. One source claims that for the most optimal growth of a plant, it is better to be exposed to 90% red light, and 10% blue light. Adding or removing the other light colors will vary the appearance and texture of the plant you are growing and will cause your plant to grow with the characteristics that you seek.

What Happens If Your Plants Do Not Receive Enough Light?

When plants do not get enough light, multiple things could happen and trust us, there’s nothing positive that could happen! Here are a few signs that could help you determine if your plants are not getting enough light: Yellow Spots – this is due to lack of chlorophyll since the plant is not getting enough light to produce more of this.

Plant’s Growth – You’ll notice that your plants aren’t getting tall when it should be.

Extended Internodes – This is the spacing between the leaves. If your plants do not get enough light, the spaces between the leaves of your plants will be bigger.

Small Leaf size – Since the leaves are not producing energy and food, it won’t grow as it should.

Leaning – Since your plants are struggling to get enough light, the tendency is it will look for what it needs, so you’ll notice that the plant itself will extend and lean towards the light. However, it will not seem like it’s growing healthily as it will look like it’s having a hard time leaning towards the light.

How Does Light Intensity Affect Plant Growth?

This is an important aspect when it comes to using grow lights. You don’t want to fry your plants up during the time it is exposed to lights. The light intensity can be manipulated through distancing the light from your plants.

The distance of your grow lights will really depend on the type of grow lights you will use. Some growers go for metal hides, and HPS grow lights, while some use fluorescent grow light or LED grow lights.

Metal Hides and HPS grow lights can create an intense heat during the time it is on, while LED grow lights doesn’t really produce much heat.

Generally, you can do the hand test to know if the heat that your grow lights are producing is becoming somewhat harmful than helpful.

The hand test is done by simply placing your hand under your grow lights, just above your plants, for about thirty seconds.

If you find the heat too much to bear with that duration, then it means that you should be putting more distance between your grow lights and your plants.

Always remember to have this checked to avoid mishaps. Your plants could wilt, dry up, weaken, or worse, die if you leave them exposed to the high heat produced by your grow lights.