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Which wavelengths of light are absorbed by plants for photosynthesis?

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Diagram of a tree leaf illustrating photosynthesis, with arrows showing sunlight, water, and carbon dioxide entering the leaf and sugars and oxygen being produced. A person is shown beside the tree to demonstrate the exchange of oxygen and carbon dioxide between plants and animals. — Photosynthesis Diagram of photosynthesis showing how water, light, and carbon dioxide are absorbed by a plant to produce oxygen, sugars, and more carbon dioxide.

Plants absorb electromagnetic radiation with wavelengths between approximately 400 and 700 nanometers for photosynthesis. This range corresponds to the visible light spectrum.1

Within this range, chlorophyll—the primary pigment in plants—absorbs light most efficiently in the blue and red portions of the spectrum. Specifically, blue light has a wavelength of approximately 450 nanometers, while red light falls within the 650–700 nanometer range.21

Because chlorophyll does not efficiently absorb green light, that portion of the spectrum is reflected, which is why many plants appear green to the human eye. In addition to chlorophyll, plants utilize accessory pigments such as carotenoids and carotenes to absorb light at different wavelengths, effectively broadening the range of light energy that can be captured and transferred to chlorophyll for use in the photosynthetic process.2134