Posted: 27/04/2015 at 17:39
I almost replied before but I've never grown this dianthus. It looks like an indoor variety,,doesn't It?
however, I would treat it like the usual garden vwrieties, viz., grow it outside and take cuttings as normal. As soon as frost risk is over I would plant outside in a warm sunny spot. Harden it off by putting it outside during the day for a few days first.
during the summer take pipings/.cuttings of basal shoots and pot them up with a view they will not be hardy over winter. Grow,the cuttings onion gh.