Is something wrong with my Dianthus?

[NotAnEMERGENCY]

I got 3 pots of Dianthus Pink Kisses from B&Q in May. They did great over the summer but now all look like this.

Is this normal for Dianthus Pink Kisses at this time of year or is something wrong with it?

Am I supposed to cut the brown bits off now or should I wait till spring?

It doesn't look happy, does it? there are a number of diseases which affect Dianthus - rust, various wilts and other fungal disorders. I think I'd be tempted to cut all the foliage off, and see if it recovers next spring, I don't think I'd leave it as is, in case it infects other plants nearby.

Right - I'll try that. Thanks, Nan!