Overview
Uses: Hedges, screens, foundation plantings, and as a pollinator for female hollies.
Benefits: A dense, pyramidal male blue holly with glossy dark green, spiny evergreen leaves. It does not set berries, but it is the pollinator that lets female hollies like Castle Spire® produce their red winter fruit.
USDA Hardiness Zones: 5–8
Sun: Full Sun to Partial Shade
Life Cycle: Broadleaf Evergreen Shrub
Growth Habit: Pyramidal, Upright — dense and full.
Bloom Color: White (small)
Foliage Color: Glossy Dark Green
Mature Height: 8–10 feet
Mature Width: 4 feet
Bloom Season: Spring
Growth Rate: Moderate
Summary
The dense, dark evergreen that makes a holly hedge berry up.
Blue hollies are either male or female, and only the females carry red berries. Those berries form only when bees bring pollen from a male holly growing nearby. Castle Wall® is that male partner. It has the same glossy, dark foliage with a bluish cast, the same spiny leaf edges, and the same dark purplish stems as the berried forms, so it blends right into a planting of female hollies like Castle Spire®.
It is also a handsome evergreen on its own. The plant grows as a dense, full pyramid eight to ten feet tall and only about four feet wide, a shape that suits a screen along a property line or a tall foundation planting at the corner of a house. The prickly leaves make a hedge that people and pets tend to walk around rather than through.
In spring, small white flowers open along the stems. They are not showy, but bees visit them steadily, and that traffic is what carries pollen to the female plants. The real show comes in winter, when the dark leaves look their richest against snow.
Care
Castle Wall® Blue Holly Care
Plant in full sun to partial shade. Sun produces the densest growth. In the colder part of its range, a spot sheltered from strong winter wind and harsh late-winter sun helps prevent leaf browning.
Blue hollies prefer moist, well-drained, slightly acidic soil with some organic matter. Avoid low spots where water stands, and very alkaline soil, where leaves can turn pale.
Water deeply once or twice a week through the first growing season while roots establish. Established plants tolerate short dry spells but look best with steady moisture. Water well in late fall before the ground freezes, since evergreen leaves keep losing moisture through winter. A two-to-three-inch layer of mulch helps.
Feeding needs are light. One application of a slow release fertilizer in early spring is plenty.
Prune or shear in late winter or early spring before new growth begins. The plant takes shaping well and fills back in densely, so it can be kept as a clipped hedge or left to grow as a natural pyramid.
Size
What Size is the Castle Wall® Blue Holly for Sale Online?
Our Castle Wall® Blue Holly ships in a greenhouse-grade grow pot and is appropriately sized for its container at the time of shipment. As an evergreen, it keeps its leaves through the off-season. If you have specific sizing or planting questions, please contact us.
How Large Does Castle Wall® Blue Holly Grow?
Expect about 8 to 10 feet tall and about 4 feet wide at maturity, in a dense, upright pyramid. Space plants about 3 to 4 feet apart for a continuous hedge or screen.
Additional Information
What is the botanical name of Castle Wall® Blue Holly?
The botanical name is Ilex × meserveae Castle Wall® ‘Heckenstar’. It is a Proven Winners® ColorChoice® shrub selected for its dense, pyramidal habit.
What are some common names for this plant?
It is a blue holly, also known as Meserve holly.
Does Castle Wall® produce berries?
No. It is a male plant, so it flowers but does not fruit. Its job is to pollinate female blue hollies, such as Castle Spire®, so they can set their red winter berries. Plant it within roughly 40 feet of the females; one male can serve several female plants nearby.
Can it be used for a hedge or privacy screen?
Yes. Its narrow, pyramidal form and dense evergreen foliage make a solid screen without taking up much ground. Mixing it into a row of female blue hollies gives you a screen that also carries berries. See more Privacy Trees & Shrubs and Evergreen Plants.
