I'm a first-time grower of cosmos, and I think I messed up by keeping my seedlings indoors for too long. They've ended up too leggy, and I've repotted them individually, making sure that most of the leggy root is covered in potting mix. They've been placed back in my coldframe, but I'm unsure how to help them grow from here. Should I give them direct sunlight every day by taking them out of the coldframe, or is it better to keep them inside? Any tips would be greatly appreciated!
4 Answers
I'd suggest potting some more just to be safe; you never know how they’ll turn out. It could be worth it!
Cosmos are pretty sturdy, so even those leggy ones should do fine. Just remember not to overwater, and they should be okay in the coldframe as long as it’s not freezing!
Honestly, cosmos are pretty easy to grow. If your seedlings are really leggy, you might want to consider starting fresh since you still have some time. Balance is key though—you want to give them enough light while keeping them warm. If I were you, I’d keep them inside on the sunniest windowsills and rotate them for even light. If you take them outside, be cautious of the cold—especially at night, it’s too chilly to leave them in the coldframe. A heated windowsill propagator is a great investment if you have the budget; mine was about 30 pounds and it really helps with late planting!
Actually, I didn't think you could bury the stems of seedlings that aren't tomatoes or chilies. I thought they would just rot. But I'd be happy to learn more if someone has a different take on this!
You can actually! Many plants, including cosmos, can form roots along a buried stem through a process called layering. It's a common method for them.