[LilacSandy]

Can anyone tell me what to do with my Cosmos seedlings,  I had a cracking display at the lotty and they have self seeded all over the place.  Do I leave them where they are, do I dig them up and overwinter in the cold greenhouse, or will they die with the frosts?

[sunshineband]

Cosmos like this are half hardy annuals  (Mexico is there homeland) so you will need to bring them inside for the winter and keep them snug 

[LilacSandy]

Thanks Sunshine

[sarajane]

You might find that they also germinate in the spring too.  My potato patch (because I didn't weed properly) had dozens of them, standing proud and bright amongst the spuds . They looked lovely and wish I had taken a photo but they disappeared a couple of weeks ago when the spuds were dug up.  Shame

[sunshineband]

Deep in the soil the seeds of half hardy annuals often surprise you -- we had a rather lovely display of blue lobelia amonst the beetroot this summer 

You can be sure if you actually planted them now, even dee down, they wouldn't come up 

[LilacSandy]

Brilliant, thanks all, I will dig a few up to try to overwinter in the cold greenhouse.  I have also taken some seeds to sew if they do not make it. 
They brightened my house all over the summer, have only just finished last week and they look fantastic at the lotty, and best of all the bees love them.

[Trillium]

Buried seeds will live through winter and sprout in spring, but any seedlings up now and left outside will very likely die off if you get a repeat of the last 2 winters.