How to Get the Best Usage out of Grow Lights


One of the main concerns when growing plants indoors is whether they receive enough light. Under-lighted plants are weak, fruit or flower poorly, and are more prone to disease and death. Grow lights are fluorescent bulbs that provide the light spectrum a plant needs to thrive, but regular fluorescents can be easily substituted. Using grow lights correctly allows you to get the best use out of the investment, ensuring your plants remain healthy even when natural light is limited or unavailable.

Step 1

Install a two-tube light fixture over a table or counter using the hardware included with the fixture. Smaller fixtures are available that only require two screws to install.

Step 2

Place one cool-white tube and one warm-white tube in the fixture. Or, use two specially-made grow light tubes.

Step 3

Set the plants under the lights so that the top of each plant is 6 inches beneath the fluorescent tubes. Stack empty boxes or phone books under the plants to elevate them to the proper distance.

Step 4

Leave the lights on for twice the length of time of daylight hours needed for the plant, as detailed on the plant label. Generally, vegetables require eight hours of sunlight or 16 hours of grow lights. Flowers and other medium-light plants may only require 12 hours under the grow light.

Step 5

Adjust the plants as they grow to maintain the 6-inch distance between them and the lights. Do not let the leaves touch the tubes as this can damage the plant.

Tips and Warnings

  • Most plants need a period of darkness in order to rest, otherwise they wilt. Plug the lights into a timer so you don't have to turn them off and on each day.

Things You'll Need

  • Fluorescent fixture
  • Fluorescent tubes
  • Boxes


  • University of Hawaii: Growing plants indoors under supplemmental lighting
  • Utah State University:Instructions for growing dwarf crop plants under electric lights
Keywords: using grow lights, indoor gardening, gardening under lights

About this Author

Jenny Harrington has been a freelance writer since 2006. Her published articles have appeared in various print and online publications, including the "Dollar Stretcher." Previously, she owned her own business, selling handmade items online, wholesale and at crafts fairs. Harrington's specialties include small business information, crafting, decorating and gardening.