LED vs fluorescent for seed starting
The extension sources accept both. They differ on how close each should hang, and fluorescent tubes need replacing sooner.
| Question | Fluorescent | LED |
|---|---|---|
| Hanging distance | 1 to 2 in (Maryland), 2 to 3 in (Utah State), 4 to 6 in (Iowa State), 6 to 8 in (Oklahoma State) | About 8 to 12 in (Iowa State). UNH example: 8 h at 8 in or 16 h at 20 in |
| Brightness guidance | Shop fixtures work, hung close (Iowa State, Illinois, Utah State) | Iowa State: full-spectrum LED of at least about 3,000 lumens. Mississippi State: shop lights at roughly 2,000 to 3,000 lumens or more, hung close |
| Wear | Illinois: output declines with use, and some gardeners replace tubes yearly | The sources reviewed give no replacement figure |
| Hours | Iowa State: 12 to 14 h for a standard fluorescent shop fixture | 14 to 16 h is the common figure for seedlings |
| Tube ends | Oklahoma State: tube ends lose about 3 in of intensity | Depends on the fixture |
How to choose
- Choose on the fixture's published numbers: watts, lumens and length. Compare them with the sources above.
- If you already own a fluorescent shop light, extension sources say it works. Hang it close and replace tubes as they age.
- If you are buying new, the linkable LED bars in the gear shortlist show what a published specification looks like, and the shop lights page covers what to check.
- Whichever you choose, mount it so you can raise it. See hanging height.
Sources
- University of Maryland Extension: Care of vegetable seedlings
- Utah State University Extension: Starting vegetable seeds indoors, seeding culture and transplanting (2025)
- Iowa State University Extension: How do I set up supplemental lights for my seedlings?
- Iowa State University Extension: What type of lights should I use to start seedlings indoors?
- Iowa State University Extension: Will a fluorescent light fixture provide sufficient light for seedlings?
- Oklahoma State University Extension: Lighting can be tricky when starting seeds indoors (January 2024)
- University of Illinois Extension: Starting the garden, supplemental lighting for indoor seed starting (2020)
- Mississippi State University Extension: LED lights for starting seeds indoors
- Mississippi State University Extension column, "Shop lights are an economical way to sow seeds indoors" (reprinted in the Sequim Gazette)
- UNH Cooperative Extension (Jonathan Ebba): Growing seedlings under lights (PDF)
Related
- Can you use shop lights to start seeds?
- How Far Above Seedlings Should Grow Lights Hang?
- How Many Hours a Day to Run Seedling Lights
- Leggy Seedlings: Is It the Light?
- Cool White vs Red-Blue Grow Lights for Seedlings
- Seed starting shelf light calculator
- Main guide to grow lights for a seed starting shelf