Color: White Flower Size: 5-7″ (12-18cm) Flowering Period: June-Sept Mature Height: 9-12′ (3-4m) Pruning Group: B2 Planting Aspect: Sun/ Partial Sun / Bright Shade USDA Zone: 4 Foliage: Deciduous Suitable for Container: Yes Price Group: Standard About Jackmanii Alba If left unpruned, Jackmanii Alba produces loosely formed double pale bluish-lilac, 5-7″ (12-17cm) flowers followed by single blooms from June to September. Mature height 9-12′ (3- 4m). Pruning group B2 or C.