Some of my favorite blue flowering shrubs with their common names in parentheses are: Ceanothus veitchianus 'Julia Phelps' (California Lilac) zones 7-9, Caryopteris clandonensis 'Sunshine Blue' (Blue Beard or Blue Spirea) zones 6-9, Buddleia davidii 'Nanho Blue' (Butterfly Bush) zones 5-9, Hibiscus syriacus 'Blue Satin' (Rose of Sharon) zones 5-8, Hydrangea macrophylla 'Nikko Blue' and 'Blue Wave' zones 4-9.
