My whole batch of heirloom tomato seedlings got leggy under my new grow light

I set up a 150 watt LED panel in my basement for my Brandywine starts, but I think I hung it a foot too high. They all stretched toward it and got super weak stems after about ten days. What's a good rule for hanging height with LEDs for veggies?

3 comments

3 Comments

elliotl241mo ago

Yeah I used to just hang my LED wherever it looked right and hope for the best. But after seeing how fast the stretch happens with heirlooms I started measuring every time. @umaprice mentioned the 6 to 8 inch start and that matches what finally worked for me too. I keep a ruler taped to the shelf so I can check quick before I walk away.

umaprice2mo ago

Honestly used to think you could just eyeball the height with LEDs. Then I killed a whole tray of peppers the same way. The general rule that finally worked for me is to start with the light about 6 to 8 inches above the seedlings, and then you have to raise it as they grow. Those weak stems are such a pain to fix.

joseph_hart2mo ago

Measure from your plants, not the ceiling. I keep my LED about a hand's width above the seedlings (like 4-6 inches) and check it every couple days. If it feels warm on your hand at leaf level, it's probably too close.