Inkberry
Ilex glabra
also called gallberry, inkberry holly
The native answer to boxwood: a soft rounded evergreen with small glossy spineless leaves and jet-black berries, taking the same shearing and the same foundation plantings without boxwood's blight.
- Type
- Shrub · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Sunlight
- Full sun to part shade
- Watering
- Moderate; a swamp native that forgives the drip line
- Soil
- Acid, moist to wet; tolerates ordinary beds
- Feeding
- Gentle all-organic
- USDA zones
- 4b–9b
- Frost tolerant
- Yes
- Plant out
- at the last spring frost
- Plant spacing
- 3 ft 11 in
- In-row spacing
- 3 ft 3 in
- Between rows
- 4 ft 11 in
- Square-foot density
- Not suited to SFG
- Root system
- Woody and fibrous
- Working depth
- 12–24 in
- Can reach
- 3 ft down where the soil allows
- Spread
- 10–13 ft across, about 1.5–2× the width of the plant
- Shallowest pot
- 20 in of soil
A shallow woody framework with the fine feeding roots in the leaf litter above it. Those feeders are mostly under the outer half of the canopy rather than against the stem, which is where water and feed should go.
It suckers into a colony and goes bare at the base with age, which is why it is cut back hard every few years rather than trimmed.
The habit is Inkberry’s own; the figures are what that habit usually comes to at this size, not a measurement of this species. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
- Cats and dogs
- Recorded toxic
Recorded as toxic to cats and dogs by ASPCA.
The ASPCA files the common name Inkberry under Ilex opaca; our catalog names Ilex glabra.
- When
- Not harvested. One spring shear or thin keeps it dense.
- What to look for
- The straight species going leggy at the ankles; any form getting loose after a few unpruned years.
- How to harvest
- Shear lightly after the new growth hardens, or thin a few oldest stems at the base for a softer look. It rebreaks from old wood, so even a hard renewal works.
- How often
- Once a year, or less for the compact cultivars.
- Storing the crop
- Nothing to store. Leave the black berries on the females; the winter birds take them once the showier fruits are gone.
- Iron chlorosis Iron chlorosis on alkaline foundations backfilled with builder's rubble
- Bare lower stems with age in the straight species; the compact cultivars were bred against it
As box blight spreads, this is the shrub landscapers quietly substitute. The species goes bare-ankled with age, which the modern compact cultivars were bred to fix, so buy a named one. Berries (on females) fed the "inkberry" name; colonists really did write with them.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com