Shoo-Fly Plants - flowering size

ju1i3

This may be a challenging query. I'm growing shoo-fly plants for charity. I hadn't set out to but as I found they had germinated well and were growing well they were be a good way to support the charity. I have potted them up in what I thought were pretty large pots but I'm worried they won't flower unless they are in even larger pots. Has anyone grown them before, in a pot (and what size), and can give me some idea how tall they get before they flower? thank you

This one is 53 cm tall in a pot that is 22 cm diameter and 17 cm tall.

hogweed

Mine grew to about 3 foot in the ground. Are you going to be selling the plants, or the seeds?

ju1i3

the plants, in flower if possible and in a reasonable pot, ie not too too large, maybe it's not possible and I'll have to think again, I have about 10 large plants as above