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 dark 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.
In the taxonomical name, Ilex gabra, 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. However, be aware that the leaves and berries have toxic qualities to both humans and pets.
|Common Name||Inkberry holly, gallberry, Appalachian tea|
|Botanical Name||Ilex glabra|
|Mature Size||5-10 ft. tall, 5-8 ft. wide|
|Sun Exposure||Full, partial|
|Soil Type||Moist, well-drained, clay|
|Hardiness Zones||4-10 (USDA)|
|Native Area||North America|
|Toxicity||Toxic to people, toxic to pets|
Inkberry Holly Care
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 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 after it is established and more so 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.
Types of Inkberry Holly
There are a few varieties of inkberry including:
- 'Densa' grows to 4 to 6 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 to 5 feet in height and width. It has bright green foliage and is known to sucker less than other varieties.
- 'Nigra' grows 6 to 10 feet in height and width. It has dark green foliage.
- 'Nordic' grows to 3 to 4 feet in height and width. It has dark green foliage, with a distinct broad pyramidal growth habit, and has larger leaves 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. Some species tend to get leggy and should be pruned in the early spring to reshape and allow the plant to fill out. The blooms on inkberry are on old wood, not the new growth, so if you want to see the flowers bloom, it's best to wait till after the blooms are spent to prune the plant. Remove root suckers regularly if you don't want the shrubs to colonize and spread.
Propagating Inkberry Holly
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, which can be planted in other areas of your yard if you'd like.
If you want to propagate them on your own, you can do so with cuttings. Here's how:
- Using pruning shears, cut off a 6-inch piece of new growth from a healthy branch.
- Dip the cut end into a rooting compound powder or gel.
- Select the appropriate spot for your new plant and push the cut end into the soil, approximately 1-inch deep, and water. Keep the soil moist but not over wet.
You can also put cuttings in water to root, which will take about four weeks. And then plant in the desired location.
Inkberry holds up well during the winter months and doesn't require being covered unless there is going to be a freeze. Interestingly enough, some species will have their leaves turn a deep purplish color in the winter.
Common Pests and Diseases
Inkberry is a very easy-to-grow plant with few serious insect or disease problems and is deer-resistant. Leaf spot is an occasional problem. Spider mites sometimes appear, especially in dry conditions. Powdery mildew, a fungi, can appear mainly in warm and humid environments. These issues can be taken care of with a fungicide or neem oil treatment. The shrubs are also susceptible to chlorosis (yellowing of the leaves) if they are planted in high pH alkaline soil.
How deep should you plant inkberry holly?
Inkberry holly should be planted just to the top of the root ball. If you plant up to where the branches meet the roots, that's too deep.
How long do inkberry holly live?
With the right conditions and proper care, inkberry holly can live for 40 years or more. There are some holly plants that have lived as long as 100 years.
What are common companion plants to put with inkberry holly?
Plant some viburnum, hydrangea, or rhododendrons along with inkberry. Some edging plants that look well in front of inkberry holly include impatiens, geraniums, begonias, and coleus.
Holly Berries. Poison Control, National Capital Poison Center.