Check your library to see if they have a copy of Carnations and Pinks for Garden and Greenhouse by John Galbally. It has everything you'll ever need to know about growing Dianthus.

The link below is to a short article at Allwoods about growing Dianthus from seed. You should treat Chabauds like Perpetual Flowering Carnations.

Here is a link that might be useful: Dianthus from seed

Thank you bellegallica that was very informative! i'll have to check out the book.