How to Build Grow Lights


Indoor grow lighting systems are very useful for many home gardeners. With an indoor grow lighting system, you can grow plants indoors year-round that require a higher level of light than you can provide with windows. You can also start vegetable seeds indoors several weeks before your average last frost date. This enables you to plant decent-sized plants into your garden versus seeds, which means an earlier harvest. Building a grow light system requires a few common household tools.

Step 1

Decide where you will construct your grow light system. Pick a location that has easy access to an electrical outlet and is not overly drafty.

Step 2

Select a light fixture that is best suited for the area in which you will be growing. You can find fluorescent fixtures in 2-foot and 4-foot lengths.

Step 3

Pick out light bulbs that benefit the plant. Plants almost entirely use light from the blue and red spectrums only. The green and yellow spectrum is not readily used for photosynthesis, therefore your bulbs should give off light primarily in the red and blue spectrums.

Step 4

Figure out how your plants will be set up in the grow area. Once you have determined how they will be set up, you can then determine the elevation the lights need to hang at. The bottom of the light bulbs should be 2 to 4 inches above the top of your plants.

Step 5

Look at the top of your light fixture. You will notice the light fixture has two locations where it will be hung from. Measure the distance between these two points.

Step 6

Use your stud finder and locate a ceiling joist above the location you will be setting up your plants. Mark out two points along that joist that correspond to the distance between the two support locations on the light fixture.

Step 7

Drill a 1/8-inch hole into the ceiling joist at each marked location. Screw in a hanging hook into each hole and tighten with your pliers.

Step 8

Cut two lengths of chain at a length that allows your light fixture to suspend 2 to 4 inches above your plants. Attach the chains to each hanging hook. Suspend the light fixture by attaching the chains to the supports on the light fixture.

Step 9

Install the light bulbs into the grow light fixture. Read the fixture's instructions to see how the bulbs are installed to that specific fixture.

Step 10

Set up your plants under the grow light. Use a table as necessary to get the plants within 2 to 4 inches of the light.

Step 11

Plug an automatic timer into your electrical outlet and set it to keep the grow light on 16 to 18 hours per day and off from six to eight hours. Plug the grow light into the automatic timer.

Step 12

Adjust the grow light upward as necessary as the plants grow. Maintain the plants at a 2- to 4-inch distance from the light bulbs.

Tips and Warnings

  • Grow lights that are kept too far away from plants will cause the plants to "stretch" or grow toward the light. These plants will become tall, spindly and weak.

Things You'll Need

  • Fluorescent light fixture
  • Fluorescent light bulbs
  • Tape measure
  • Stud finder
  • 1/8-inch drill bit
  • Hanging hooks
  • Pliers
  • Chain
  • Bolt cutters
  • Automatic timer


  • Wayne's This and That: Fluorescent Plant Lighting
  • University of Missouri Extension: Lighting Indoor Houseplants
  • University of Alaska Fairbanks Cooperative Extension Service: Fluorescent Lights for Plant Growth
  • University of Hawaii at Manoa: Growing Plants Indoors Under Supplemental Lighting
Keywords: build grow lights, install grow lights, fluorescent fixture, hanging hooks, distance from plants

About this Author

Robin Gonyo has been writing for several years now. She has a deep love for gardening and has spent a vast amount of time researching that subject. Previously she has written for private clients before joining Demand Studios. She hopes to share her knowledge with others through her writing.