Started some late last year they have over wintered and seem to be growing nicely now will they just grow to seed ?
Keep em wet .... they're a swamp plant in the wild, how big are they?
Have they been growing under cover? Cold weather is usually cited as a cause for them bolting, but maybe it's worth a try. If any don't bolt, it would be worth saving seed from them to select for the trait. I'd be interested in an update later in the season.
I would be really interested to know your results. I would think they will bolt and i'm suprised the slugs haven't made a mess of them as they do mine if I leave them in too long. Pls let us know what happens.