Posted: 07/10/2013 at 23:12
Leave them be. Once I'd planted one, there are dozens year on year, self setting. I sometimes catch the seed of one particular colour, but all I do is scatter it elsewhere and it grows. Very low maintenance!
If the site is very exposed, you can pot some up and keep in a greenhouse until spring, but even in an exceptionally cold winter you are unlikely to lose them all!