I just love garden pinks, every year I plant an edging of pinks and after every winter they have disappeared What am I doing wrong?
Probably nothing - many of them are actually annuals.
If yours are definitely perennials, then drainage may be the issue - dianthus don't like cold, wet soil and do best when kept fairly dry over winter.
We are on clay here so our borders are full of water for a couple of months each winter, and I've never lost any of my pinks that are all round the edge. So I dont think it's the wet, more likely the type you grow, as Alina says maybe you buy annual ones.