Homegrown Habitat, December 2024: Inkberry
Inkberry tolerates drought, inundation, salt, compacted soils, erosion, and air pollution. It’s rare in the wild in Connecticut but the cultivars are common in parking lot plantings, gardens, and elsewhere. (Photo by David J. Stang, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons)
Inkberry is one of my garden staples. Its glossy evergreen foliage and upright, vase-shaped form is welcome in many locations, from the foundation beds to a mixed shrub border, and areas where a bit of screening is needed. I love it in combination with other evergreens such as mountain laurel, rhododendron, and spruce or fir, where the subtle differences in the green hues of their foliage is featured delightfully.
Ilex glabra, a member of the holly family, is also known colloquially as Appalachian tea and gallberry. It is native to much of eastern North America, from Nova Scotia to Florida and west to Texas. In the wild it is often found in moist areas like wetlands and streambanks but also thrives in sandy, salty seashore settings. Wild populations of inkberry are considered rare and threatened in Connecticut and endangered in Maine and New Hampshire.
This adaptable plant prefers full sun but grows well (albeit more slowly) in shade. I have seen it growing wild in dense shade, but most sources recommend sun to part shade. Acidic soil is a must. Inkberry tolerates drought, inundation, salt, compacted soils, erosion, and air pollution, but it does not appreciate being transplanted.
In typical garden settings, expect inkberry to reach a height of five to eight feet and a breadth of three to five feet. Some cultivars, however, are smaller, and the straight species can grow taller. Inkberry has a tendency to sucker and can form dense thickets in the wild.
Small greenish-white flowers, which attract pollinators, appear in spring. On male plants the blooms form in clusters; on female plants they appear singly or in threes. The flowers produce a nectar that results in honey that is highly prized, and some beekeepers grow inkberry just for this purpose. But many native bees and butterflies also seek out the nectar and pollen of inkberry flowers.
Blue-black fruit (drupes) follow the flowers and will persist until November if the birds don’t eat them earlier. Small mammals also enjoy the fruit. Inkberry foliage is said to be deer and rabbit resistant.
The Ilex species serve as a host plant to more than 40 species of lepidoptera, including the holly clearwing, io, and polyphemus moths. Their caterpillars eat the foliage and in turn are preyed on by songbirds to feed nestlings.
As noted above, inkberry is suitable for many garden settings. Rain gardens, roadside plantings, evergreen screens, and mixed shrub borders or hedgerows will all accommodate inkberry. Use it in combination with winterberry and perhaps summersweet clethra in a moist area for terrific bird habitat and winter interest.
An inkberry thicket. This photo was taken in New Jersey, where the soil can be highly acidic. Growth patterns like this are probably not typical in the wild in Connecticut. (Famartin, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons)
Inkberry is often recommended as a native substitute for the non-native boxwood. It is far less prone to pests and diseases. Inkberry tolerates loose pruning, which is best done in late winter. Flowering and fruiting occur on old wood. The growth habit of inkberry exposes more of its lower limbs than does boxwood’s, so you may want to underplant it with a dense groundcover, such as a sedge, to fill in the base of the shrubs.
Inkberry, like all hollies, is dioecious–meaning that plants are either male or female, and only the females bear fruit. A male is needed nearby (one for every four or five females) for flower pollination and fruit production. Unfortunately it is difficult to find male inkberry plants for sale, since most of the cultivars offered by nurseries are female. The many female cultivars include ‘Shamrock,’ ‘Nordic,’ ‘Nigra,’ ‘Densa,’ ‘Compacta’, and ‘Cape Cod.’ Finding male inkberry companions for your female shrubs is a big challenge.
This market imbalance poses a dilemma for well-meaning gardeners eager to provide fruit-bearing plants for birds. Kim Eierman, horticulturist, ecological landscape designer, and author, urges gardeners to pressure their local plant sellers to offer straight species (not cultivars), including male inkberries. But until these plants are more widely available, we may have to resort to getting them from mail-order native plant nurseries—rarities in their own right.
To all of our readers, we wish you joyful holidays. I’ve so enjoyed your feedback over the year and look forward to more in 2025. Looking for a New Year’s resolution? Plant more plants that attract caterpillars! This will be a beautiful gift to birds, helping to sustain them in these harrowing times. And remember — never use pesticides, which is explained so well in the Connecticut Audubon Society’s 2024 State of the Birds report, published in November. Here’s to a new year bursting with birds! — Sarah Middeleer, homegrown@ctaudubon.org.
Resources
Books
Anna Fialkoff et al., Native Shrubs for Northeast Landscapes, Wild Seed Project, 2023
Stephen W. Kress, The Bird Garden A Comprehensive Guide to Attracting Birds to Your Garden throughout the Year, DK Publishing, 1995
Websites
How do I find a “mate” for my Inkberry? – EcoBeneficial®
Ilex glabra (Appalachian Tea, Gallberry, Inkberry) | North Carolina Extension Gardener Plant Toolbox
How to Grow and Care for Inkberry Holly
