Q. How does colored light affect plants?


Blue light, red light and green light each have a different effect on plants.

Blue light produces more lush greenery. Blue light is necessary for plants to regulate plant growth, as it helps to create strong stems and also helps create the chlorophyll necessary for plant processes.

Red light is needed by plants to flower, but if a plant receives too much red light it will become brittle and die. Blue light is a must when growing plants; for flowering varieties, red light is also necessary.

Green light is not used very much by mature plants. Some studies have suggested it is useful when a plant is germinating but not beyond. The reason that green plants appear green is that they reflect rather than absorb the green waves in the light spectrum. In other words, the chlorophyll in the plant absorbs the red and blue light much more readily than the green light.

Plants that get natural sunlight receive all the colors in the spectrum. But if you decide to grow plants using artificial light you need to consider how much blue light, red light and green light are given off by the artificial light. Usually the packaging indicates these amounts.


For tips on a variety of gardening topics, see our Plant Information Guides.
Courtesy of NYBG Plant Information Service


  • Last Updated Apr 02, 2018
  • Views 6417
  • Answered By Anita Finkle

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