Holly, Castle Spire® Blue HollyCastle Spire Blue Holly is a compact evergreen shrub with a densely upright pyramidal habit and glossy dark blue green toothed foliage. Its bright red berries display in fall and winter. Best planted in moist, slightly acidic well drained soils. Hollies are dioecious and need both male and female plants to produce fruit. Type: Shrub Origins: I. aquifolium x I. rugosa Hybrid Height: 6' 10' Spread: 3 4' Spacing: 3 USDA Hardiness Zone: 5 7 Culture: Full