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Pinching out Cosmos

harmonyharmony Posts: 351
My cosmos were started on my windowsil and are now in my plastic covered mini greenhouse. For the last few days I have been putting them on the patio and back in the greenhouse at night. My questions are how far  do I pinch back, are they ready to be pinched back yet and when I put them on the patio to harden them off are they better in a shady spot or in the sun. It is my first time growing from seed (apart from calendula and nasturtium s) so I want to give them the best start. Also how big do they have to be before they are planted out I have a sunny space waiting. Thanks


  • AnniDAnniD Posts: 11,153
    I know not everybody pinches them back. My varieties Rubenze and Dazzler are quite leggy in comparison to the Brightness Mix ones, which are very stocky plants.
    They look very healthy, l think as soon as the roots start to show l would plant them out.
    Which variety are they ?
  • harmonyharmony Posts: 351
    They are Sensation mix
    I have just bought the dwarf mix orange carpet that I am thinking of sowing in a pot now.. 
  • I always pinch out cosmos sensation as it's a very tall cosmos and without pinching the central stem grows very thick and long and often needs support. I pinch the top growth tip with my fingers, within a couple of days you should see new side shoots appear. It feels wrong to pinch a growing plant, but pinching actually stimulates the side leaf nodes into action and results in a fuller, bushier plant. 
  • harmonyharmony Posts: 351
    I have never bought cosmos as a bedding plant so didn't know anything about them, last year someone gave me 3 cosmos plants and I fell in love they are so beautiful. If I pinch will they grow shorter?. I have been looking at the dwarf varieties for pots as well. Can I ask you how far down do you pinch.
  • Nanny BeachNanny Beach Posts: 8,343
    I grow them regularly bright lights,purity, this year I never pinch out

  • AnniDAnniD Posts: 11,153
    If you want to try pinching them out, you could hedge your bets and just do half of them. I take off just the top,take it down to the next set of leaves. Hope that makes sense.
    If you Google "pincing out Cosmos", there are several videos on YouTube. Some are a bit full of waffling though.
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