1 named cultivar

‘Brunswick Giant’Brunswick Giant Ebony Spleenwort

fernN. America Native

Ebony Spleenwort

The Story

Plant Bio

Asplenium platyneuron, ebony spleenwort, is a small evergreen fern native to North America east of the Rocky Mountains, with a disjunct population in southern Africa. Once-divided fronds carry many small alternate leaflets along a glossy dark purple-brown stalk, which is the feature that names it. Fertile fronds stand upright to about fifteen inches while sterile ones spread flat in a low rosette.

It is unusually tolerant for a fern, growing in dry rocky ground, old walls and thin woodland soil where most ferns will not persist, and it stays green through winter. The two frond types are worth knowing: the flat spreading rosette is not a struggling plant but the sterile form, which behaves quite differently from the erect fertile fronds.

Uses & Benefits:

Fine evergreen texture and glossy dark stalks in places too dry and shaded for other ferns.

Colonises rock crevices, old walls and thin dry soil where little else establishes.

Provides year-round shelter for ground-dwelling invertebrates in woodland.

Essentials

At a Glance

Plant Type

Fern

Height

15 inches

Width

15 inches

Light

Partial Sun, Shade

Zones

4, 5, 6, 7, 8, 9

Water

Low

Humidity

Moderate

Lifespan

Perennial

Native To

North America east of the Rocky Mountains

Toxicity

Non-toxic

Planting

How to Grow

Plant in spring in well-drained soil with plenty of leaf mould.
Choose dappled to deep shade.
Set the crown at soil level, never buried.
Water to establish, then only in extended drought.
Mulch lightly with leaf litter each autumn.
Remove damaged fronds in early spring, leaving healthy ones.

Pro Tip

Give it sharp drainage rather than constant moisture — this is a rock and wall fern, and it rots in heavy wet soil.

Keep It Thriving

Care Guide

Do

Plant in shade with good drainage 🌱
Mulch with leaf litter each autumn 🍂
Use it in rock crevices and wall pockets 🪨
Leave the evergreen fronds over winter ❄️

Don't

Plant it in heavy, wet soil ❌
Bury the crown ❌
Cut all the fronds back; it is evergreen ❌

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Monitor
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Shaded rock garden and wall creviceDry woodland underplantingEvergreen groundcover in deep shade

Companion Plants

Christmas Fern Wild Ginger Foamflower Woodland Phlox Alumroot

Multiply

Propagation Methods

Good to Know

Common Questions

Ebony Spleenwort questions

What zones can Ebony Spleenwort grow in?

Ebony Spleenwort is hardy in USDA Zones 4–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Ebony Spleenwort deer resistant?

Yes — Ebony Spleenwort is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.

When does Ebony Spleenwort bloom?

Ebony Spleenwort typically blooms in non-flowering through late fall. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Ebony Spleenwort need full sun?

Ebony Spleenwort does best in part shade.