onion seedlings with yellow tips

Asked March 16, 2015, 11:52 AM EDT

I am growing onions from seeds indoors which are about 1 month old. They tips started to turn yellow about 1 week ago. I have them under a grow light and on a window sill and water them every day. I cut off some of the yellow tips (not sure if that was a good idea?). The yellow seems to be spreading so I'm afraid to lose all my seedlings. I apply an organic seaweed fertilizer (through a spray bottle) about twice a week. Is there anything I can do to save these seedlings?

Baltimore County Maryland

1 Response

From your photo it looks like the onions may be subject to too much moisture. Watering every day may be too much. Water to keep the media moist, but not wet. It’s OK if the surface of the growing media dries a bit. Make sure the containers have holes for good drainage.

Also, the soil mixture should be a soilless mixture which is a mixture of peat moss, perlite, and vermiculite which promotes good drainage. Avoid dense heavy potting mixtures and garden soils.

Place the transplants 1 to 2” beneath the light fixture for 14 to16 hours a day. Attaching thin chain or wire to either end of your light fixture will allow you to raise and lower the tubes. If the lights are too far away from the transplants, then they will be leggy.
You do not have to trim the yellow tips. Follow the label directions for the fertilizer.

See our website for information on Starting Vegetable Seeds Indoors.