The most difficult part of growing Dianthus species is avoiding crown rot in wet, poorly draining soil. I planted several Dianthus in troughs last year and lost them to a cold, wet winter. However, the Dianthus growing in a raised bed that was mulched with about two inches of rock survived the winter without difficulties. Therefore all future Dianthus will have at least one inch of pea gravel-sized mulch. Like all plants, Dianthus do have some problems.
Slugs seem to like their tender foliage.
However, growing these in a rock-mulched raised bed eliminates this problem. Cutworms like to cut the plants down and rabbits love to eat the buds just before they burst into bloom. Although I have had no problem with slugs or cutworms, I have given up growing the carnations because the local rabbits got every bud regardless of what I used to try to deter them. If Dianthus are in too wet of a soil, various fungal diseases may attack them. A thorough clean-up in the fall eliminates many winter hiding places for pests and diseases.