Cosmos flowering already

[namechange2222]

I planted quite a few cosmos seeds and kept them on a really sunny window sill. They're now about 8 inches tall, really healthy looking but some are already starting to flower.
What do I do, the weather seems still to cold to put them out but I planted later last year and didn't have this issue as they didn't flower until late summer
Can anyone advise please? Do I take a chance and put them out now or continue with these huge plants indoors?

I would pinch out all of the growing tips, so that they bush-up instead of flowering. I'd also start putting them outside (a sheltered spot on a patio would be ideal) in the daytime.

Thanks so much TheHoundsofLove I'd given up anyone answering! I'll do exactly that and put them out in my outhouse over this weekend then plant out on Monday

Depending on where you are, I wouldn't plant them out yet in case of overnight frost. I'm putting my Cosmos seedlings out in the day, but then bringing them back in at night.

Yes prune them back, harden them off and then plant out in a week or so.

Ah sorry read the advise wrong! OK I'll start hardening them in the daytime and put them in out house at night
Oh and so pissed off to see that the so called 'chocolate' cosmos are actually pale pink!

I grew cosmos from seed last year and every single one died. Germinated lovely, but then just stopped, and flopped and shrivelled. Three different varieties.

Can't make up my mind to try again.

Chocolate cosmos are a sterile [tender] hybrid, they don't set seed and only grow from cuttings or division as they are a perennial, you have been scammed there.

Where did you get the seeds from?

I’m avoiding Cosmos this year, mine grew like triffids, we’re 5ft tall with huge thick stems they didn’t flower till late summer and covered everything else in the bed.

Blimey!

TERFragetteCity Ebay and from China!!!!
But only cost about 99p so not too scammed. However to be petty I've written to the sellers asking for an explanation, pity I'd already given feedback. Pity though as I hate pale pink / mauve in flowers
JT05 similar to mine last year but this year I've got huge borders that need filling so will be pleased if they do as well