Light and Plants

• Plants need light for a variety of reasons. They harvest solar energy to turn into plant sugars from the sun and can also harvest energy with artificial light. Plants respond to photo-sensory cues that tell them when to germinate, sprout and flower. These cues come from the duration and intensity of light exposure. Sunlight provides an array of light wavelengths that include red, orange, green, yellow, blue, indigo and violet. Blue and red light wavelengths are the most important to plant growth.
  
  

Blue Lights

• Blue light is responsible for vegetative growth in plants and is a component of fluorescent lights, which is why plants grow well in that type of artificial lighting. Blue lighting encourages leaf development and doesn't help flowering or seed production. A plant grown under blue light will have a thick, strong stem and many green leaves. It will also be rather stumpy and stunted because red light is what makes plants grow tall. However, plants grown under only red light will be slim and spindly.
  
  

Artifical Lighting and Plants

• Plant health can improve even under artificial lights. Plants with supplemental outside lighting will show better health and flower production with even just a couple of hours of additional artificial light. A plant can also be grown entirely in artificial light but must have both red and blue lighting wavelengths for optimum growth. Too much light inhibits flowering, but red light encourages the production of flowers. The flowering plant needs at least 6,000 to 10,000 lux, which is a measurement of candle lengths or light units. Using a reflector can enhance the light and help encourage the growth in the length of the stems.
  
  

Growing Paperwhites Under Lights

• Paperwhites are ideal plants for forcing indoors where bulbs are made to bloom even when it is not the right time of year by a combination of temperature and planting conditions. Plant the bulb with the pointed side up in 2 parts potting soil with 1 part sand mixed into it. The bulbs have no chilling requirements to break dormancy, so they can be potted immediately. Place the pot in a dim area, and don't move it to light until the bulb sprouts; then place it under fluorescent lights that are 10 to 15 inches above the pot. You may also use special grow tubes that have the proper blend of blue and red light for optimum plant growth. The paperwhite will reach its maximum height of 3 feet under a combination of light wavelengths and with good water and nutrients.