Castle Wall® Blue Holly

Castle Wall® Blue Holly is an upright, columnar evergreen male holly with glossy dark-green leaves and small white spring flowers. It produces no berries; plant it near female Castle Spire® or Castle Keep® hollies when pollination is needed ([Proven Winners](https://www.provenwinners.com/plants/ilex/castle-wall-blue-holly-ilex-x-meserveae), [NC State Extension](https://plants.ces.ncsu.edu/plants/ilex-x-meserveae/)). ## Planting and use Give it full sun to part shade and acidic, moist, well-drained soil. Its narrow shape works as an evergreen hedge, screen, foundation planting, or specimen. Proven Winners lists mature size at 5–8 feet tall by 3–4 feet wide, while NC State's entry for Castle Wall® 'Heckenstar' gives 8–10 feet by about 4 feet; these are approximate published ranges and size varies with growing conditions ([Proven Winners](https://www.provenwinners.com/plants/ilex/castle-wall-blue-holly-ilex-x-meserveae), [NC State Extension](https://plants.ces.ncsu.edu/plants/ilex-x-meserveae/)). ## Cultivar and flowering The recorded selection is Ilex x meserveae 'Heckenstar'. Its white flowers open in spring; the male plant supplies pollen for nearby female cultivars but does not set berries. The original patent record lists Heckenstar as PP 14,308, dated November 18, 2003 ([RHS](https://www.rhs.org.uk/plants/177152/ilex-%C3%97-meserveae-hecken-star/details), [Justia](https://patents.justia.com/inventor/hans-hachmann)). ## Maintenance Mulch to help retain soil moisture. After flowering, prune only as needed to shape; its natural habit needs little trimming. Keep the soil acidic and moist but well drained ([Proven Winners](https://www.provenwinners.com/plants/ilex/castle-wall-blue-holly-ilex-x-meserveae), [NC State Extension](https://plants.ces.ncsu.edu/plants/ilex-x-meserveae/)).