I know they're biennial, but do any of you leave them where they are and do they flower OK again the following year. Mine are all just going over now, but they been a lovely show. Thanks
Cut them back fairly hard once they have finished flowering so they do not become straggly and they should give a good show again next year. However, they are easy to sow from seed - I have mine sown already but if you hurry they should grow big enough before the winter comes.
I collect the dried seed heads and shake them over the flower beds get at least a few replacement plants each year for no real effort do the same with foxgloves ,verbascum and aquilegia the forget me nots manage on their own