Virtues: Small-space gardeners will delight in Blue Puffball chastetree (Vitex agnus castus ‘PIIVAC-II’ or Blue Puffball). This long-blooming shrub stays short and compact, making it an easy addition to city gardens or tight corners in established beds and borders. Flowers and foliage are fragrant.
Common name: Blue Puffball chastetree
Botanical name: Vitex agnus-castus Blue Puffball or ‘PIIVAC-II’
Flowers: Dark blue-purple fragrant flowers appear at the tips of Blue Puffball’s branches from late spring to autumn.
Foliage: Scented gray-green thick but willowy leaves cover the branches. This chastener’s foliage tends to stay clean and free of leaf spot through the fall.
Habit: This small chastetree grows 3 to 4 feet tall and wide. The name Blue Puffball refers to its flower color and its overall shape.
Season: Summer, for flowers.
Exposure: Full sun.
How to grow Blue Puffball chastetree: Provide moderate water. Flowers form on new growth, so if you want to prune Blue Puffball chastetree, you should do so in early spring, before growth begins. Given this dwarf vitex’s naturally compact shape, though, pruning is not likely to be necessary. USDA Zones 6–9.