How to Grow and Care for Inkberry Holly

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 glabra, the species epithet, glabra, 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.

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 is also a good native substitute for boxwood and privet hedges.

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.

Light

This shrub prefers full sun, especially in cooler climates. It can, however, tolerate partial sun and may appreciate some shade in warmer areas.

Soil

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.

Water

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.

Fertilizer

Fertilize in spring with a fertilizer such as Holly-Tone. If your soil is alkaline, consider amending it before 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

Pruning should be done in late winter or just after blooming. Inkberry blooms on old wood, so pruning needs are minimal unless you are using the shrubs in a hedge. Some species tend to get leggy and should be pruned in late winter to reshape and allow the plant to fill out. Because the blooms on inkberry are produced on old wood, not the new growth, you might sacrifice flowers and fruit if you wait too long to prune. 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:

1. Using pruning shears, cut off a 6-inch piece of new growth from a healthy branch.
2. Dip the cut end into a rooting compound powder or gel.
3. 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.

Overwintering

Inkberry holds up well during the winter months. 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.