It depends on what kind of Dianthus you have, Finn. Many of them will bloom for a pretty long time, but only bloom once. If you have the ones that are sold with the bedding plants in spring and are usually considered to be annuals (but they do come back for a few years!), I find it best to cut them down to about an inch above the ground when they've finished their primary bloom. If you do that, they should come back and give you another bloom that's pretty close to the first one. If you just leave them, as you seem to have found out, they'll kind of keep blooming a little bit for most of the rest of the summer, but won't look that great anymore, and deadheading is almost impossible.

If you have some other species, I'd have different advice. Do you know what the Latin name is for the ones you have? Dianthus whatus???

I'll be incommunicado for a few days, but maybe if you know what they are somebody else will have a recommendation.

Skybird

Thanks Skybird! I don't know what the species is but, yeah, they are the ones that are sold as annuals. Good, I'm glad I can just cut them back. That will be much easier. Thanks again!