Large clusters of flowers (white, pink or blue), in summer; flower form depends on cultivar, some have "lacecap" flowers (small fertile flowers surrounded by showy fertile flowers), others have a globose form (all larger, sterile flowers); summer foliage is a lustrous, bright green.
Numerous cultivars available including
- 'All Summer Beauty' - Flowers heavily and often reblooms.
- 'Bailmer' (Endless Summer®)- Blooms on new wood, so even if plant dies to the ground in winter, it will flower the following summer.
- 'Nikko Blue' - Large globose flowers (blue only in acid soils).
Blue flower color will only be produced in acid soils, usually in the 5.0-5.5 range.
This shrubs grows in zone 5, but does not usually flower there. This species flowers on last year's wood and in zone 5 the plant dies down to the ground so there is no old wood. New cultivars are being selected for flowering on new growth (see cultivars).