Inkberry holly is a slow-growing broadleaf evergreen shrub with a rounded-to-upright growth habit. It is easy to grow and offers good winter color.
The name "inkberry" is a clear reference to the fruits produced by the shrub, as is the plant's secondary common name, "gallberry." This alternate name derives from the fact that black ink was once made from the galls of oaks.
The taxonomical name, Ilex gabra, features the genus name Ilex, meaning "oak." This is probably a reference to the similarity of the leaves to those of the holly oak (Quercus ilex). The species epithet, gabra, means "smooth," referring to the plant's smooth leaves, which are quite different than the prickly leaves of more common hollies.
|Botanical Name||Ilex glabra|
|Common Name||Inkberry holly, gallberry shrubs|
|Plant Type||Evergreen shrub|
|Mature Size||Five to eight feet in height and spread, although several cultivars have a more compact, smaller form|
|Sun Exposure||Full sun to part shade|
|Soil Type||Rich, consistently moist, acidic soils|
|Flower Color||Greenish white|
|Hardiness Zones||4 to 10|
|Native Area||American coastal plains from Nova Scotia to Texas|
How to Grow Inkberry
Inkberries are dioecious (meaning there are separate male and female plants). Female plants need a male pollinator if you want them to produce the berry-like fruits. A single male plant is usually all that is required.
A popular choice for areas with damp soil, such as woodland gardens and plantings around bogs and ponds, Inkberry prefers full light and moist soil. Inkberry has glossy dark green oval-shaped leaves; greenish-white flowers appear in May and June, giving way to pea-sized black fruits that mature by early fall. The native form of inkberry is somewhat shaggy and leggy and tends to spread by suckering, so landscape plantings tend to use one of several cultivars that have better form and better behavior.
Inkberry shrubs work well massed or grouped for shrub borders and are also used in foundation plantings or for low, informal hedges. Inkberry works well in moist locations, such as woodland gardens are around landscape ponds and water features.
Inkberry shrubs hold up well to polluted urban conditions. Bees are fond of the flowers, and the resulting honey has a highly prized, unique flavor. Inkberry is sometimes planted as a source of food for beehives. Wild birds are also drawn to inkberry. Inkberry is resistant to deer, and thus is a good choice in areas where browsing deer are a problem for other shrubs.
This shrub prefers full sun, especially in cooler climates. It can, however, tolerate partial sun and may appreciate some shade in warmer areas.
Inkberry is best planted in average, medium to wet soils and in full sun to part shade. It is adaptable to both light and heavy soils but does best in rich, consistently moist, acidic soils. It does not do well in alkaline soils. In native locations, it prefers sandy, acidic woodland soils and is often found along the edges of swamps and bogs.
Inkberry needs quite a bit of water, established as it is becoming established. You will need to water at least once a week, especially if the weather is dry.
Temperature and Humidity
Inkberry holly thrives in a wet, cool climate. This distinguishes it from other hollies, which often prefer drier locations.
Fertilize in spring with a fertilizer such as Holly-Tone. If your soil is alkaline, consider enriching it with peat moss when planting your inkberry.
Inkberry self-propagates by spreading root suckers. In fact, it can take over an area rapidly if it's not checked. You can slow the pace of growth by removing the suckers each year.
Varieties of Inkberry
- Densa grows to 3 to 4 feet in height with a slightly greater width.
- Compacta grows to 3 to 4 feet in height with a spread up to 6 feet. It has a tighter, more rounded growth habit than other forms.
- Shamrock grows to 4 feet in height and spread. It has bright green foliage and is known to sucker less than other varieties.
Pruning should be done in early spring just before new growth emerges, but pruning needs are minimal unless you are using the shrubs in a hedge. Remove root suckers regularly if you don't want the shrubs to colonize and spread.
Inkberry is a very easy-to-grow plant with few serious insect or disease problems. Leaf spot is an occasional problem. Spider mites sometimes appear, especially in dry conditions. The shrubs are also susceptible to chlorosis (yellowing of the leaves) if they are planted in high pH alkaline soil.