Dave's Garden PlantFiles - Profile page with horticultural basics, and member-contributed photos and comments. (zone 3-9) (2 photos)
Denver Botanic Gardens - Description, native range, and cultural requirements. (additional pages for other varieties) (zone 3). Also a page for 'Blue Glow'.
Missouri Botanical Garden - Plantfinder page for one of the plants growing at the garden, with usually one or more photos, horticultural information, and noteworthy characteristics. (zone 4-9). Also pages for 'Blue Globe' and 'Blue Glow'.