perennial

Black Arum

Arum x diotalicum 'Jet Black Wonder'

The Story

Plant Bio

Arum are tuberous perennials known for their arrow-shaped leaves and unique inflorescence, which consists of a spadix surrounded by a spathe. Many species are winter-growing and summer-dormant.

The 'Jet Black Wonder' cultivar is renowned for its deep, nearly black foliage and striking dark-colored spadices, adding dramatic contrast and visual interest to shaded garden areas.

Uses & Benefits:

Provides striking black and white foliage year-round, adding drama and contrast to shaded areas.

Prefers moist, well-drained soil, making it suitable for shaded garden beds.

Supports local pollinators when in bloom, though blooms are less conspicuous.

Essentials

At a Glance

Plant Type

Perennial

Height

24 inches

Width

18 inches

Light

Partial Sun, Shade

Zones

5, 6, 7, 8, 9

Water

Moist but well-drained

Humidity

Moderate to high

Lifespan

Perennial

Native To

Europe, North Africa, Western Asia

Toxicity

All parts are highly toxic if ingested; may cause skin irritation.

Bloom period

Early spring – Late spring

In flower about 3 months of the year

Planting

How to Grow

Tuck rhizomes 2 inches deep in well-draining soil.
Water regularly to keep soil moist but not soggy.
Place in partial shade for best color development.
Mulch to retain moisture and suppress weeds.
Fertilize with balanced fertilizer in early spring.
Monitor for pests and remove any affected foliage.

Pro Tip

Ensure soil stays moist and provide partial shade for vibrant foliage.

Keep It Thriving

Care Guide

Do

Water consistently during growing season 💧
Mulch to conserve moisture and regulate soil temperature
Prune dead leaves to maintain appearance
Apply balanced fertilizer in spring

Don't

Avoid overwatering to prevent root rot ❌
Don’t expose to full sun, which can scorch leaves
Refrain from disturbing rhizomes during dormancy

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Divide
Fertilize
Plant

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Dark foliage as a dramatic border accentShade garden centerpieceMoist woodland garden feature

Companion Plants

Hostas Ferns Astilbe Ligularia

Multiply

Propagation Methods

Good to Know

Common Questions

Black Arum questions

What zones can Black Arum grow in?

Black Arum is hardy in USDA Zones 5–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Black Arum deer resistant?

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

When does Black Arum bloom?

Black Arum typically blooms in early spring through late spring. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Black Arum need full sun?

Black Arum does best in part shade.