The Story
Plant Bio
Arisaema tosaense is a perennial herbaceous plant featuring distinctive, umbrella-like foliage and striking spathe flowers that display a mix of green and purple hues, thriving in woodland settings.
This species is appreciated for its resilience in shaded environments and unique floral structure, making it a popular choice for shade gardens and woodland landscapes.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Perennial
Height
18 inches
Width
12 inches
Light
Partial Sun, Shade
Zones
5, 6, 7, 8, 9
Water
Moist but well-drained
Humidity
Moderate to high
Lifespan
Perennial
Native To
Japan
Toxicity
Toxic if ingested
Bloom period
Early spring – Mid-spring
In flower about 2 months of the year
Planting
How to Grow
- Tuck seeds into moist soil in fall for natural stratification
- Plant rhizomes 2 inches deep in well-draining soil
- Water regularly to keep soil moist but not waterlogged
- Position in partial shade for best growth
- Mulch around plants to retain moisture and suppress weeds
- Monitor for pests and remove any affected foliage
Pro Tip
Ensure soil remains moist and well-drained for optimal growth
Keep It Thriving
Care Guide
Do
- Water consistently during dry periods 💧
- Apply mulch to conserve moisture
- Plant in partial shade for best foliage color
- Remove dead leaves in early spring
Don't
- Avoid waterlogging soil ❌
- Don't expose rhizomes to direct full sun
- Refrain from over-fertilizing
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fertilize | ||||||||||||
| Mulch | ||||||||||||
| Plant |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Multiply
Propagation Methods
Good to Know
Common Questions
Tosa Cobra Lily questions
What zones can Tosa Cobra Lily grow in?
Tosa 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 Tosa Cobra Lily deer resistant?
Yes — Tosa Cobra Lily is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does Tosa Cobra Lily bloom?
Tosa Cobra Lily typically blooms in early spring through mid-spring. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Tosa Cobra Lily need full sun?
Tosa Cobra Lily does best in part shade.
More Arisaema to compare
Japanese Cobra Lily
Arisaema ovale
Jack-in-the-pulpit
Arisaema triphyllum
Himalayan Cobra Lily
Arisaema consanguineum
Arisaema engleri Green Spathe Form
Arisaema engleri 'Green Spathe Form'
Nebraska Green Dragon
Arisaema dracontium 'Nebraska'
Japanese Jack-in-the-Pulpit
Arisaema serratum
Keep exploring
Explore the genus
Hardy in your zone?
Grow Tosa Cobra Lily with confidence
See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.