By Delks
United Kingdom 
could you tell me if cosmos are hardy, if so can i cut them down and leave in the garden over winter. Or do i have to set seeds again for next year. Mrs J E elks
3 Sep, 2011
Answers
Seaburngirl, the 'chocolate' one never survives a winter here in London, even a mild one. I've given up and don't grow it any more, too expensive to replace yearly. The Cosmos I now grow are the annual kind.
4 Sep, 2011
THANKYOU VERY MUCH
6 Sep, 2011
depends on which ones you mean. the chocolate one is a perenial but in a severe winter you would lose it. The others in shades of pink and white are an annual and will die i the first frosts. You can collect the seeds from these are buy new for next year. the seeds you collect will vary from the plant depending on which cosmos pollinated it. Hope this helps.
welcome to GOY
3 Sep, 2011