Here are a few that I trialed last year. The ones marked with an asterisk have assuredly survived the horrible winter we just had; the rest aren't showing obvious signs yet, but it's still very early.
Penstemon (Penstemon x mexicali 'Carillo Purple')*
Carpathian Bellflower (Campanula carpatica)*
Hedgerow Cranesbill (Geranium pyrenaicum 'Bill Wallis')*
Current-leaf globe-mallow (Sphaeralcea grossulariifolia)*
Cottage Pink (Dianthus plumarius 'Velvet 'n' Lace')
Maltese Cross (Silene chalcedonica 'Dusky Salmon')*
Blackfoot Daisy (Melampodium leucanthum)
Hyssop (Agastache aurantiaca 'Sunset Yellow')
Seed Box (Ludwigia alternifolia)
Alpine Catchfly (Silene suecica)
