Leave it as it is. The seed heads will develop, the browen outer covering will fall off and you will be left with attractive papery, silver discs. These can be cut for flower decorations.

Thanx for your reply. The seed heads are developing now and I will scatter the seeds if I catch them before they do it themselves and thats fine. But its the plant itself I dont know what to do with as they are quite large and take up a lot of room.
Will the same plant root flower again? If not I was thinking I might just as well pull them up - what do you think?
Thank you

You could pull them up once you have collected some seeds. Whats the harm in that? Go for it Dipadee. Welcome to GOy

Well thank you. I found the site by chance and its so good to 'chat' to people about the thing I love - my garden and the plants in it. I might just give nature a hand and scatter the seeds soon, then I can remove the plants and make room for all the other plants that are waiting to go in the ground. I have loads of tubs and this year I am trying to plant as much in the garden as pos . . .

You will have to wait until the seed pods develop as Bulbaholic says. Pulling the plant up now will stop these developing I'm afraid. The flat, disc-like seed pods get up to three inches in length and turn tawny coloured before the two outer layers drop off to reveal the silvery membrane that separates them. The seeds are flattened round discs about 1cm across. You can see when the seed pods are ripe as they start to change from green easily enough and you can take the plant up then.

By the way, it's a biennial so the plant will not grow again anyway. The resulting plants from the seeds will not flower until their second year.

lol Dipadee, Ive said that for years and always end up putting things in pots!!!!! Its like I cant help myself lol