My cosmos from last year have self seeded. First time they have done that. Cosmos seem to like an early sowing ..then lots of heat and humidity in the greenhouse during may
Mine are smaller, but ok I guess seeing as I don’t have a greenhouse and only 2 small windowsills, so everything gets ‘hardened off’ early lol! I have found though, that the slugs are favouring the white ‘purity’ over the pink ‘dazzler’ perhaps coincidence...
Ryan when did you plant the seeds,mine don't look nearly as good as yours,all leggy and thin! Lyn,shall I put mine in deeper pots?? Normally I just chuck the seed straight on the ground,but read that the plants will be stronger if nurtured in a pot indoors!
Pinch out the top of the larger ones(which at least three pairs of leaves) to make them bush out. You get more flowers that way. Harden them off for a few days by standing them outside so the breeze can get at them. If a frost is threatened this week then cover them up or put back in cold frame at night. Then you should be OK to plant out at the weekend.
Posts
https://forum.gardenersworld.com/discussion/996397/pricking-out-cosmos#latest
They usually go on til late October here.