Red And Blue Light For Plants

The arizona master gardener manual which was produced by the cooperative extension of the university of arizona s college of agriculture discusses some of the effects.

Red and blue light for plants.

It s also essential to a plant s early life for seed germination root growth and bulb development. Red light is responsible for making plants flower and produce fruit. Blue promotes root development and strong stocky plant growth. The amount of blue red and far red spectrum of light that reaches the planet changes with the seasons.

However when a relatively small amount of blue light is added to red light extension growth of plants is inhibited. When you blast your young plants with blue you prepare them to sustain a ton of buds in the future. Blue light is helpful for growing leaves on plants. Therefore red is very efficient at producing fast growing tall and strong plants and indeed produces some of the most impressive growth rates of height and stem width in plants.

Our perception of blue light especially at shorter wavelengths for example 400 to 425 nm is low compared to green. As days start to get longer more blue spectrum light reaches the surface of the earth. For certain plants like christmas cactus this manipulation is the only way to guarantee the plant will be in bloom over the holidays. Red light when mixed with blue can assist with the flowering portion of a plant s growth.

Blue light also affects flower and fruit preparation and production but blue light alone produces short plants of a dark color. Plants use the blue spectrum to stimulate early growth. Plants that receive plenty of blue light will have strong healthy stems and leaves. Therefore plants grown indoors with 80 to 90 percent red light and 10 to 20 percent blue light are quite compact with smaller leaves and shorter stems.

Red light is ideal to maintain healthy mature plants. In contrast blue light is considered equally effective as green or red light at driving photosynthesis. If a plant receives some sunlight a gardener can manipulate it by adding appropriate blue and red spectrum light to encourage healthy growth and fruiting and flowering. Thus while blue light can appear somewhat dim to us it has high energy and is useful for plant growth applications.

A higher intensity of red promotes a higher yield. Red and blue wavelengths. Red light on the other hand does its best work in the flowering phase. This initiates a vegetative growing stage for most plants leading into the spring and early summer.