I've never tried any Dianthus in a pot. I try not to pot anything that doesn't have to come inside because it's just that much more watering for me to do. I hope my new patch of D. gratianopolitanus does not fail in the heat but I've never had that one in AL before & have no idea what to expect. It will take a few yrs before I see what D. gratianopolitanus can & can't do where I am now. In any case, I'll welcome those scented blooms any time they feel like showing!
The other ones that I have (D. barbatus) have been blooming literally non-stop for over 2 yrs, through frozen temps up to the heat of summer.