How do I set up supplemental lights for my seedlings?


How do I set up supplemental lights for my seedlings?


Supplemental lights need to oriented relatively close to the seedlings to be effective and therefore need to be adjustable in height to accommodate the growing plants.  For most fluorescent fixtures, the seedlings should be 4 to 6 inches from the light source.  LED fixtures can often be set a little further away at about 8 to 12 inches from the plants.  Hang light fixtures from adjustable cables or chains so they can be moved up as the plants grow or place seedling trays on blocks or bricks that can be removed to lower trays as they grow.

Provide adequate air circulation around the seedlings to dissipate heat produced by the light fixture.  Place lights on a timer set to turn fixtures on for 14 to 16 hours a day.

Learn more about providing supplemental light for seedlings indoors in this article: Growing Indoor Plants Under Supplemental Lights.

seedlings under lights

Answered by
  • Specialist
  • Consumer Horticulture Extension
Last updated on
March 19, 2024