I noticed MrCushy posting pics of this same flower... are related, is it the same flower?

Hi, Yes I beleive it is, Cornflower I think, I'm not good with plant names but learning, they really give a good show this time of year but have a tendancy to take over

It is a great flower - nice colours.

Can it be grown in a pot to keep it at bay?

not to sure, i didn't plant mine they just appeared, they do spread though