Lucky you. You have seeds to fill your garden. The usual method is; after flowering, pluck the dried heads off and shake them into a paper bag until all those long black-white tipped seeds fall off. (Failing that, pull 'em off.) Save them until about mid-March...a bit earlier if you have a warm place, and scatter them on top of compost in a seed tray. DON'T cover them. Most of them will germinate if their healthy. When big enough to pr*ick out, pot on individually intp paper pots and plant out when the weather warms up a bit. Also good in the greenhouse border.