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Iris ensata 'Cascade Spice' (Cascade Spice Japanese Iris)
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© Krzysztof Ziarnek, Kenraiz, some rights reserved (CC-BY-SA) · Wikimedia Commons

Iris ensata 'Cascade Spice'

Cascade Spice Japanese Iris

Garden selection; species native to Japan, Korea, China, and Russia

At a Glance

FoliageDeciduous
Height24-36 inches (60-90 cm)
Width18-24 inches (45-60 cm)
Maturity3 years

Growing Zones

USDA Hardiness Zones

4 - 9
These zones indicate the coldest temperatures this plant can typically survive.
What's my zone? →
Frost Tolerancehardy

Overview

Iris ensata 'Cascade Spice' is a Japanese iris, growing 24–36 inches (60–90 cm) tall and 18–24 inches (45–60 cm) wide. Lavender-pink flowers 6–8 inches (15–20 cm) across with darker veining — the falls (lower petals) are held horizontally, creating a flat, wide flower form rather than the upright-and-pendant form of bearded iris (I. germanica). Flat horizontal falls are the genus-section trait of Japanese irises. Compared to other iris types: bearded iris (I. germanica) has upright standards + pendant falls, tolerates drought, and is susceptible to iris borer; Siberian iris (I. sibirica) has narrow falls, tolerates wet soil, and has fewer pest issues; Japanese iris (I. ensata) has flat wide falls and requires acidic wet conditions. Requires acidic soil (pH 5.0–6.5) and consistently moist to wet conditions during the growing season — drier during winter dormancy. Blooms later than Siberian iris — late spring to early summer. Deer-resistant. Mildly toxic. Zones 4–9. Grows from fibrous rhizomes planted 1–2 inches (2.5–5 cm) below soil surface (not exposed like bearded iris). Full sun to light shade. Crown rot develops in alkaline or waterlogged winter conditions. Growth rate is moderate. Divide every 3–4 years to maintain vigor.

Native Range

The species is native to Japan, Korea, China, and Russia.

Suggested Uses

Grown in borders, pond edges, and rain gardens in zones 4–9, spaced 18–24 inches (45–60 cm) apart. Acidic soil (pH 5.0–6.5) with consistent moisture during the growing season. Full sun to light shade. Deer-resistant. Mildly toxic.

How to Identify

Identified by large lavender-pink flowers 6–8 inches (15–20 cm) with flat horizontal falls on a clumping perennial growing from fibrous rhizomes. The flat wide falls distinguish Japanese irises from bearded (upright + pendant) and Siberian (narrow falls). Requires acidic wet conditions.

Appearance

Size & Dimensions

Height2' - 3'
Width/Spread1'6" - 2'

Reaches mature size in approximately 3 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~3 weeks
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Late spring to early summer, 2–3 weeks. Lavender-pink flowers 6–8 inches (15–20 cm) with darker veining. Flat horizontal falls. Blooms later than Siberian iris.

Detailed Descriptions

Flower Description

Lavender-pink with darker veining — large, FLAT, elegant flowers (the Japanese iris form = flat, not upright standards like bearded iris)

Foliage Description

Dark green, narrow, sword-shaped, upright — more blade-like than Siberian iris

Growing Conditions

Sun Requirements

Requires 4-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.0 - 6.5(Acidic)
357912
Soil Types
Drainagemoist

Water & Climate

Water Needs

High

Frost Tolerance

hardy

Time to Maturity

2-3 years for full display

Care & Maintenance

Care Guide

Full sun to light shade. Acidic soil pH 5.0–6.5. Consistently moist to wet during growing season; drier in winter dormancy. Crown rot in alkaline or waterlogged winter soil. Divide every 3–4 years. Deer-resistant. Mildly toxic. Zones 4–9.

Pruning

Remove spent flower stems at the base. Leave foliage through fall — cut to ground after browning. Divide clumps every 3–4 years in late summer.

Pruning Schedule

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fall

Maintenance Level

moderate

Container Growing

✓ Suitable for container growing

Minimum container size: 7 gallons

⚠️ Toxicity Warning

Toxic to pets and humans