Usually I am the one with the garden fails, but my dianthus came back very happily this year. I bought past-their-prime plants about this time last summer, and they bloomed happily with deadheading... Then I let them go to seed in late summer, and now they have been blooming happily since spring. Actually come to think of it, they were one of my first happy blooms in the spring. We had a cold winter here but quite a lot of snow, and I suspect my garden is doubly happy for the insulation of snow it got this winter.
As for blanket flowers, I have them returning in great profusion, but it's key to let them go to seed at the end of the season.
Both dianthus and blanket flowers are in full sun for me, though it doesn't get all that hot here and winters are long and cold. Blanket flowers in particular seem to thrive on neglect.
