Species

Arisaema serratumJapanese Jack-in-the-Pulpit

1 other cultivar

‘Ulleung Treasure’Ulleung Treasure Japanese Cobra Lily

perennial

Mt Fuji Form Japanese Cobra Lily

Arisaema serratum 'Mt Fuji Form'

The Story

Plant Bio

Arisaema serratum, known as Japanese Cobra Lily, is a perennial herbaceous plant with distinctive, palmately divided leaves and unique, hooded flowers that resemble a cobra's head, typically featuring white and purple markings.

The 'Mt Fuji Form' is a select cultivar prized for its striking pseudostem, which is snakeskin green with dramatic vertical white stripes, resembling snow on a mountain. The spathe is typically green and white striped.

Uses & Benefits:

Adds exotic appeal with its striking foliage and unique floral structure, perfect for shaded gardens.

Provides ground cover in shady areas, suppressing weeds and conserving soil moisture.

Supports local pollinators and enhances biodiversity in woodland landscapes.

SpeciesArisaema serratumJapanese Jack-in-the-Pulpit

Essentials

At a Glance

Plant Type

Perennial

Height

24 inches

Width

15 inches

Light

Partial Sun, Shade

Zones

5, 6, 7, 8, 9

Water

Moderate

Humidity

Prefers moist environments

Lifespan

Perennial

Native To

East Asia

Toxicity

Toxic if ingested

Bloom period

Late Spring – Late spring

In flower about 1 month of the year

Planting

How to Grow

Tuck bulbs 2 inches deep in well-draining soil
Water regularly to keep soil moist but not waterlogged
Mulch around the plant to retain moisture and suppress weeds
Place in partial shade for best growth
Divide clumps every 3-4 years in early spring
Protect from extreme cold with mulch in winter

Pro Tip

Plant in well-draining, humus-rich soil in partial shade for optimal growth.

Keep It Thriving

Care Guide

Do

Water consistently during active growing season 💧
Apply a balanced fertilizer in early spring 🌱
Mulch to conserve moisture and regulate soil temperature

Don't

Avoid overwatering to prevent bulb rot ❌
Do not expose to full sun which can scorch leaves
Refrain from disturbing bulbs during dormancy

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Fertilize
Mulch
Plant
Propagate
Spring Cleanup

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Shaded woodland gardenUnderstory border with fernsMoist, shady rock garden

Companion Plants

Hostas Ferns Astilbes Heucheras Ligularia

Multiply

Propagation Methods

Good to Know

Common Questions

Mt Fuji Form Japanese Cobra Lily questions

What zones can Mt Fuji Form Japanese Cobra Lily grow in?

Mt Fuji Form Japanese Cobra Lily 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 Mt Fuji Form Japanese Cobra Lily deer resistant?

Yes — Mt Fuji Form Japanese Cobra Lily is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.

When does Mt Fuji Form Japanese Cobra Lily bloom?

Mt Fuji Form Japanese Cobra Lily typically blooms in late spring through late spring. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Mt Fuji Form Japanese Cobra Lily need full sun?

Mt Fuji Form Japanese Cobra Lily does best in part shade.