The lack of knowledge and experience cause contradictory statements regard of plant growing. Actually, how plants react to light and how light affect to growing of a plant is quite simple subject.
The light coming from the sun which we consider as white is actually mix of different colors. The main colors of a light are red, blue, and green.
It is not possible to give an exact answer for which color is better for indoor plant growing. Plants need both red and blue light. Both colors have different affects on plants.
Most of the plants look green. Because leaves reflect the green light in large scale. Green light reflected from a plant reach to our eyes and makes us to see it green.
The leaves of plants are not seen as red or blue. Because the light spectrum absorbed these parts. In other words, plants absorb blue and red light and use this energy to grove instead of reflecting them.
Red light is basically responsible for flowering of the plant and fruit production. Red light is necessary for seed germination, root growing. 600-700 nm wavelength range red light is used to support the development of a plant and improving the taste of fruit.
Blue light provides chlorophyll production (the most active pigment for photosynthesis) in plants. Plants that receive plenty of blue light will have a strong, durable, and healthy stem and leaves.400-500 nm wavelength range blue light is used to support stem and green leaves development.
Outdoor plants can get the blue and red light sufficiently under the natural light. There may be some deficits in certain parts of the light spectrum in indoor areas. If the stem and the parts which connect the leaves to the stem are too long, if the leaves lose the green color, that means the plant is not get sufficient blue light. If the plant is not bloom, probably it is lack of red light.
Different lamps can be used for red and blue lights. Also, special plant growing lamps that offers red and blue lights together can be used. It is possible to grow many vegetables and fruits even in cold winters when the right light used without dependent on seasons.
