A curious question came in this week to Ask Gardenerd:
“Hello-I’m starting some cool season plants from seed inside my house. I planted some De Cicco Broccoli seeds in seed starting mix, and placed in a window sill. The seeds sprouted in 3 days, which was definitely exciting! But now a few days later, the little sprouts’ stems are about2 inches tall and they are falling over. What may cause the sprouts to grow too fast and become top heavy??”
First of all, congratulations on starting broccoli from seed! It isn’t always the easiest thing to get growing. It sounds like your sprouts got leggy (meaning tall and thin). The usual reason for this is that the sprouts didn’t get enough sun. Most vegetable seedlings need a lot more sun that you think, right when they break the soil’s surface — about 14-16 hours of direct sunlight. That’s why professional nursery stock growers use full spectrum grow-lights placed very close to the leaves to get their seedlings off to a good start.
If your window sill only gets 4-6 hours of light, that would be my best guess for what’s happening with your sprouts. If you have access to full sunlight for a longer period of time, try that next time.
That said, if you want to salvage your sprouts, you can give this a try:
Replant the sprouts into a deeper pot or transplant them into the ground, burying the stem up to about 1/2 an inch from the leaves. Give the sprouts full sun (as much as possible) and they should do alright. I’ve grown all the Brassicas (broccoli, cauliflower, cabbage, etc) direct-seeded in the ground and while they get a little leggy at first and fall over, they right themselves toward the sun if you bury the long stem. In the end those seedlings provided me with tender broccoli crowns and huge cabbage heads.
Hope this helps. Thanks for writing in.
