How to Use a Fluorescent Grow Light


When indoor plants don't get enough window light, supplemental lighting with fluorescent grow lights can solve the problem. Plants need light in the red and blue spectra to produce energy and live. While fluorescent grow lights provide red light, cool white fluorescent lights provide a good source of blue light. Using a combination will give your indoor plants enough light in most cases.

Step 1

Figure out how much light your indoor plants need. Low light plants need between 50 and 250 foot candles of light, medium light plants need between 250 to 1,000 foot candles of light while high light plants need more than 1,000 foot candles of light. High light plants should be placed near a bright window, and the fluorescent grow lights can be used as supplemental light.

Step 2

Screw the fluorescent grow light and cool white fluorescent lights into the lighting fixture. Use one fluorescent grow light for every one or two cool white fluorescent lights.

Step 3

Plug the lighting fixture into a wall socket and turn it on.

Step 4

Place the indoor plants under the lighting fixture. Low light plants need to be between 1 and 3 feet from two fluorescent lights. Medium light plants should be a half-foot to 1 foot from two fluorescent lights and high light plants need to be a half-foot from four or more fluorescent lights.

Step 5

Give the plants 12 to 18 hours of fluorescent light a day during the time they would get natural light or while they are getting natural window light.

Things You'll Need

  • Fluorescent grow lights, 40 watts
  • Cool white fluorescent lights, 40 watts
  • Lighting fixture


  • University of Missouri: Lighting Indoor Houseplants
Keywords: fluorescent grow lights, using grow lights, indoor plant lighting

About this Author

Hollan Johnson is a freelance writer for many online publications including Garden Guides and eHow. She is also a contributing editor for Brighthub. She has been writing freelance since 2008 and her interests are travel, gardening, sewing, and Mac computers. Prior to freelance writing, Johnson taught English in Japan. Johnson has a Bachelor of Arts in linguistics from the University of Las Vegas, Nevada.