LED Grow Light Color Spectrum for Cannabis Vegetables Tomatoes Succulents

What is a color spectrum?

Plants are genetically programmed to grow using sun light, which we consider to be white light, or yellowish-white light. This light looks white because it contains all of the colors of a rainbow, and when these colors are all mixed together they look white.
A color spectrum is a graphical display of each of the colors in the light.

Usually we use wavelength numbers to refer to the colors instead of color names, which is a much more accurate way to measure the color. So a red might have a wavelength of 630 or 660. Both of these look red to us, but they are actually different colors.
Grow lights that use florescent bulbs, refer to the color of the bulb as cool white (has more blue), or warm white (has more red). That was useful for florescent lights, but such designations do not work well for LED lights. When it comes to LED it is more accurate to talk in terms of wavelengths and to display the actual color spectrum.

What roles of different colors place in plants growth?

Red Light (630 -660 nm) is essential for the growth of stems, as well as the expansion of leaves. This wavelength also regulates flowering, dormancy periods, and seed germination.
Blue Light (400 -520 nm) needs to be carefully mixed with light in other spectra since overexposure to light in this wavelength may stunt the growth of certain plant species. Light in the blue range also affects the chlorophyll content present in the plant as well as leaf thickness.
Green Light (500 – 600 nm) penetrates through thick top canopies to support the leaves in the lower canopy.
Far Red Light (720 – 740 nm) also passes through dense upper canopies to support the growth of leaves located lower on the plants. In addition, exposure to IR light reduces the time a plant needs to flower. Another benefit of far red light is that plants exposed to this wavelength tend to produce larger leaves than those not exposed to light in this spectrum.

Best Color Spectrum Depends on Your Goals!

As plants mature and go through their growth cycle from seedling, to adult, and then flowering and fruiting they use different color spectrums so the ideal LED light is different for each stage of growth.
The best color spectrum also depends on the type of plant you are trying to grow.
This can get very complicated and is really only important for commercial growers where they want to maximize results.
As a general rule, plants do best with light of all wavelengths, but they don’t need equal amounts of each.