Well - two reasons NOT to:

1) they look great in the autumn and into winter, with their silver 'penny' seedcases, and

2) if you leave them, they'll seed themselves so you'll get new plants for free.

If neither of the above appeal, then pull the plants out, because that's it for them - they're biennials.

Thanks!
I want to keep the seed heads to use in flower decorations. Is it ok to dry them indoors, or should they be left on the plant outside? It's just they look a bit untidy.

Yes, you can dry them indoors. They don't last for all that long, but they're very decorative. :-)

Better to dry them off inside,Hazel,as they will start to go
brown and not look good in a display..tie them in a bunch,and hang them upside down,in a shed or somewhere airy..they should be almost ready now,actually...so you can just peel the outer casing off ..both sides..and dry the seeds inside,if you want to keep some.....I have just done this,but left mine in the garden for effect..maybe you would like to see my blog ,titled.." I need to get out more ".:o))

Thanks spritzhenry and Bloomer. That's very helpful.

Just checked out your blog entry on Honesty Bloomer. Very nice, thanks.

Thanks Hazel..now you know why I chose that title ! and welcome to GoY..:o)

Reminds me of once my mother sent me into the garden to gather the honesty that had seeded. In my innocence I took off all the seed pods and took them to her expecting thanks for a job well done. I thought she just wanted to save 5the seed for next year.Left the stalks in the garden. Was I thanked??? Not.

I'm not surprised! Ooops!

Sorry,but it made me laugh,Steragram..the thought was there,though !Lol.

Well I laugh now, but I didn't then and neither did my Mum!

I remember going with my mum to pick bilberries on the moors where we lived..I was about seven,and I was so excited as I showed her my tin." look mum,Rabbit's eggs"...I had collected lots of sheep muck! needless to say,she couldn't use the tin then..:o)

Fantastic ... Quite put me off my blackcurrants. And reminds me if we don't go bilberrying oon it will be too late.

Lol,Steragram....I haven't been bilberrying for years..but takes so long to pick the little devils,doesn't it ? Lots round here too,but don't think could I could manage now..all that bending and crouching !.My favourite in a pie though..Blueberries don't have that flavour at all,for me...

No, they just don't have the zing do they?