What Kind of Light Makes a Plant Grow Faster?

The color of light that a plant is exposed to has a large effect on plant growth. Light in the blue and red parts of the visible light spectrum especially affect rates of plant growth.

Blue Light

Light that appears blue occurs at wavelengths between 430 and 460 nanometers (billionths of a meter). According to Oregon State University Extension Service, blue light encourages vegetative plant growth.

Red Light

Red light occurs at wavelengths between 640 and 700 nanometers. OSU also claims that light from the red part of the visible light spectrum promotes budding and flowering in plants.

Other Light

Plants appear green not because they absorb light from the green part of the visible light spectrum but because they reflect it. White light is white because it contains all colors of the visible light spectrum.

Intensity

Generally, the more intense light that a plant receives, the faster it will grow. According to OSU, when a plant receives a lot of sunlight, it has a greater food production capacity via photosynthesis.

Duration

The more time a plant has been exposed to a light source, the greater it will benefit. In certain climates, plants have adapted to the longer day, shorter night schedule and photosynthesize according to the unusual light schedule.

References

• Oregon State University: Environmental Factors Affecting Growth
• Estrella Mountain Community College: Photosynthesis
• Colorado State Univerrsity: Plant Growth Factors, Light