Heavenly Hydrangeas, ISU Extension
"Hydrangeas, Hydrangeas" is a pretty darn good website about Hydrangeas!
I particularly liked the story of Amy-Beth and David: "The Hydrangea That Wouldn't Bloom" - Eileen
Asters for dry locations:
Aromatic Aster (Symphyotrichum oblongifolium, syn Aster oblongifolius), 'October Skies' is commonly available
Calico Aster (Symohyotrichum lateriflorum, syn Aster lateriflorus,) 'Lady in Black'
Heartleaf Aster, aka Blue Wood Aster, (Symphyotrichum cordifolium, syn Aster cordifolius)
Smooth Blue Aster, (Symphyotrichum laeve, syn Aster laevis), 'Bluebird' is commonly available
Short's Aster (Symphyorichum shortii, Aster shortii). This will go "everywhere" from seed and fill in the gaps inyour perennial garden. prune it back as much as you like through July, then enjoy the show.
Found on Facebook - why Holiday shopping for gardeners can be easy
Any Viburnum, like Viburnum nudum 'Winterthur'