Diplarrena moraea, Australian white iris
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Perennials

Diplarrena moraea

Australian white iris

Iridaceae

Southeastern Australia: Victoria, New South Wales, Tasmania

At a Glance

TypePerennial
HabitClumping
FoliageSemi-evergreen
Height18-36 inches (45-90 cm)
Width12-24 inches (30-60 cm)
Maturity3 years

Growing Zones

USDA Hardiness Zones

8 - 10
Zone 8
Zone 9
Zone 10
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancesemi-hardy

Key Features

Attracts Pollinators
Deer Resistant
Drought Tolerant
Container Friendly
Maintenancelow

Overview

A clump-forming rhizomatous perennial growing 18-36 inches (45-90 cm) tall and 12-24 inches (30-60 cm) wide. Leaves are sword-shaped, erect, and narrow, 12-24 inches (30-60 cm) long and 4-8 mm wide, mid-green, arising from the base in a fan-like arrangement. Flower stems are slender, branching, and arise above the foliage, each bearing 1-3 flowers in succession. Individual flowers are 1.5-2 inches (4-5 cm) across, composed of three large outer tepals that are white with yellow and violet markings at the base, and three smaller inner tepals that are white with purple veining. Flowers are held horizontally in iris-like fashion. Blooms appear in spring, with occasional secondary flowering possible in mild autumn conditions. Spread is by slow rhizome extension. Plants require 2-3 years to flower from divisions. Foliage remains evergreen in zones 8-10 and dies back in hard frosts.

Native Range

Native to southeastern Australia, including Victoria, New South Wales, and Tasmania, where it grows in heathlands, open forest understories, and cliff edges in well-drained, acidic soils. Commonly found in coastal and subalpine habitats at elevations up to 4,900 feet (1,500 m).

Suggested Uses

Commonly planted in well-drained borders, rock gardens, and coastal plantings at 18-24 inch (45-60 cm) spacing. Suitable for containers of at least 3 gallons (11 L) with good drainage. Self-seeds modestly where conditions suit; seedlings reach flowering size in 3-4 years.

How to Identify

Leaves are narrow, sword-shaped, and arranged in a flat fan 12-24 inches (30-60 cm) long, resembling a miniature iris. Flowers are white with yellow and purple markings at the base, 1.5-2 inches (4-5 cm) across, with three large outer tepals and three smaller, notched inner tepals. Stems branch above the foliage, bearing successive blooms. The combination of narrow fan-shaped foliage, white-and-yellow iris-like flowers, and Australian origin distinguishes it from true irises.

Appearance

Size & Dimensions

Height1'6" - 3'
Width/Spread1' - 2'

Reaches mature size in approximately 3 years

Colors

Flower Colors

white
yellow
purple

Foliage Colors

green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~5 weeks
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Spring
Blooms primarily in spring, from September to November in its native Southern Hemisphere range, or April to June in the Northern Hemisphere. In zones 8-10, occasional flowers may appear in autumn following cool periods. Individual flowers last 1-2 days; stems produce 2-4 flowers in succession, extending the display over 3-5 weeks per stem. Total bloom period per clump spans 4-6 weeks.

Detailed Descriptions

Flower Description

White with yellow and violet markings at the base

Foliage Description

Mid-green, sword-shaped, narrow, arranged in fan

Growing Conditions

Sun Requirements

Full Sun
Partial Shade
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 - 7.0(Neutral)
357912
Soil Types
loamsand
Drainage
well drained

Water & Climate

Water Needs

Low

Frost Tolerance

semi-hardy

Time to Maturity

2-3 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plant in well-drained, acidic to neutral soil with a pH of 5.0-7.0 in full sun to partial shade. Water regularly during establishment; once established, plants tolerate periods of 2-3 weeks without rain but flower production decreases under prolonged drought. Avoid waterlogged conditions, which cause rhizome rot. Fertilize sparingly with a low-phosphorus fertilizer in spring; high-phosphorus fertilizers are toxic to many Australian native plants. Remove spent flower stems at the base after flowering to maintain appearance. Divide clumps every 4-5 years when they become congested; divisions take 2-3 years to flower.

Pruning

Remove spent flower stems at ground level after flowering to prevent seed set and maintain plant appearance. Trim back dead or brown leaf tips in late winter or early spring. Full cutback of foliage is not required unless frost damages the leaves; cut frost-damaged foliage to 2-3 inches (5-8 cm) above ground level in early spring.

Pruning Schedule

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early springsummer

Maintenance Level

low

Container Growing

✓ Suitable for container growing

Minimum container size: 3 gallons

⚠️ Toxicity Warning

Unknown