spindly cosmos seedlings

Viola111Viola111 Posts: 19

This is a completely novice question, so forgive me. I sowed some mixed cosmos seed at the beginning of April, at the same time as some marigolds. They have been in the warm with lots of light on a windowsill. The marigolds have grown into lovely little sturdy plants, but the cosmos have shot up (about 2 1/2 to 3 inches tall) to become thin and leggy, and although they each now have 2 pairs of leaves they are bending over and can't stand up under their own weight. They can't cope with a fine-rose watering can and a single raindrop would flatten them! What have I done wrong? And can I retrieve the situation?

Any advice greatly appreciated! Many thanks.


  • sotongeoffsotongeoff Posts: 9,806

    You will need to get them outside to harden them off and give them better all round light.

    What you can do is, when you prick them out-bury the seedlings a bit deeper

    It is basically caused them being too warm and in low light conditions-this should help

  • Viola111Viola111 Posts: 19

    Thank you! I have been holding off putting them outside because it's been so cold, but I will get them out straight away.

  • Thanks for the advice geoff I have a similar problem, I have buried them deeper,and am now off to bring them in for the night as they are in pots in my shed,


  • I had the same problem and just potted them on, buried up to their necks and put them outside in a grow house, they're doing fine now

  • Viola111Viola111 Posts: 19

    Having left them outside during the day for the last week, and spent the weekend repotting them much deeper, they now look much happier. I might have cosmos in my garden come the summer. Thank you sotongeoff!

  • Thanks, mine are leggy too, I'll opt them a bit deeper, leave outside during the day, and take them in at night.

  • Janet143Janet143 Posts: 1

    Ditto. Ist attempt at growing cosmos from seed and they have shot up. Off to repot them now and they can go in the grow house. 

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