Plants are pretty clever than we give them credit for. As we all know, plants use light for their photosynthesis process, but did you know that the spectrum (or color) of light has different effects on the plant? In other words, the plant shifts and utilizes the different spectrum from a light source and uses it for its own growth. Amazing isn’t it?
To us, the light appears as white even though we know that it’s comprised of all the colors. Plants, however, take it to the next level and actually uses each color differently. So an obvious question that could arise from this is that what colors do they actually use and for what part. This article will focus on discussing just that together with the type of light source is best for that purpose. If you’re interested (we know you are) then keep on reading!
The light spectrum that the plant uses can be split into three – green, blue, and yellow/red. The plants use these spectrums differently during its different phases of growth. We’ll start with green as it is the simplest of the bunch.
Green lights are rather special as it’s really not used by the plants. The green pigment of the leaves can actually reflect the green spectrum of light. This is good information especially for growers as they can take advantage of this fact. For example, a lot of growers express some sort of trouble when it comes to checking their plants at night. Since plant use any kind of light, the growers can’t just use a flashlight to check their plants as it will “wake up” the plants during their sleeping time (you don’t want that to happen). This is why growers use green light to check on their plants because plants don’t use them. In other words, the plants don’t “wake up” from the green lights!
To access green light, the simplest equipment available is to use LED lights. LED lights are known to be quite softer than other lights which are great if you’re going to use green lights as the additional heat from other lights can do some damage on the plants.
The next spectrum that we will discuss is the blue light. Plants are equipped with light receivers or receptors called phytochromes and cryptochromes.Phytochromes detect yellow/red light while cryptochromes detect blue light. Blue lights received by their cryptochromes acts like a signal for the plant to grow short, stout but with full, healthy leaves. With this reason, blue lights are often used during the Vegetative Stage as it can benefit the most then. The typical blue light can be achieved with wavelengths of 420nm-460nm.
To access blue light, you can opt to use CFL or Fluorescent lighting as they are a good source of blue light. However, CFL or Fluorescent lighting are actually quite inefficient when it comes to the actual usage. Some would even say it could be impractical since plants need to be so close to it and the ratio between light produced and electricity use is inefficient. For this reason, if you want to access good blue light, you can opt to use LED lights instead.
Next, up we have yellow/red lights. If cryptochromes detect blue light then phytochromes detect yellow/red light. Yellow/red lights are actually the most important colors when it comes to photosynthesis and most flowering processes. Plants under this light tend to grow upwards towards the light which creates tall plants. For this reason, this spectrum is often used during the Flowering Stage. The typical yellow/red light can be achieved with a wavelength of 640nm-680nm.
In order to access yellow/red light, HPS or High-Pressure Sodium lights are a good source. However, LED lights also contain this spectrum but the possibility of it not being stronger than HPS is quite high. Between HPS or LED lights, HPS lights are more concentrated when it comes to yellow/red lights while LED lights are sort of a “master of none” type of light.
In general, there is no “best” light to use. In fact, some suggest that it would be actually better to have all the spectrums available for the plant but with different intensity of different spectrums during a specific growth stage!