We find that it can go through the winter in some spots and die off but
seed itself in others. If you've saved seeds, it's probably worth
trying it out this winter to see how it does with you.

If they are just at the edge where you are, then I don't suppose they
will last here - but some are still a lovely colour, so it might be
worth giving it a try.
Yes mine are still loking good, I leave them and they often survive,
well worth a go

kate