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Diplarrena spp.

white flag iris

Iridaceae Southeastern Australia and Tasmania

Attracts Pollinators Attracts Butterflies Deer Resistant Drought Tolerant Fragrant (light)Container Friendly

SunFull Sun – Part Shade

WaterMedium · drought-tolerant

HardinessZones 8–10

Overview

Diplarrena spp. is a small genus of two species of evergreen, rhizomatous perennials in the iris family, native to southeastern Australia and Tasmania. Plants form dense, grassy clumps of narrow, dark green, sword-shaped leaves 18-30 inches (45-75 cm) tall, from which slender flowering stems rise to carry a succession of iris-like flowers. The blooms are white, with three larger outer segments and smaller inner ones marked with yellow and violet, and they are fragrant. D. moraea is the more widely grown, with D. latifolia a larger mountain species. Flowering comes in late spring and summer, each flower short-lived but followed by others over several weeks. The genus grows in open forest, heath, and damp ground on moisture-retentive but free-draining, acidic to neutral soil in full sun or part shade. Plants tolerate coastal exposure and short dry spells once established but are damaged by hard frost, suiting mild-winter and maritime climates. Clumps spread slowly by rhizome into broad tufts. The narrow evergreen foliage holds through winter where temperatures stay mild. Plants reach flowering size in two to three years from division.

Native Range

Native to southeastern Australia and Tasmania, growing in open eucalypt forest, heath, and damp, grassy ground.

Suggested Uses

Grown in mild-climate borders, coastal gardens, and among grasses and shrubs for the white summer flowers and evergreen, grassy foliage. Suited to damp, sunny banks and naturalistic plantings. Plants are not reliable in cold-winter regions or on dry, impoverished soils.

How to Identify

Recognized by clumps of narrow, dark green, iris-like leaves and wiry stems carrying white, three-part flowers marked with yellow and violet. The flowers resemble small irises and are fragrant. Each bloom lasts a day or two, with others opening in succession.

Appearance

Size & Dimensions

Height1'6" - 2'6"

Width/Spread1'6" - 2'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~6 weeks

Spring Summer

Flowering comes in late spring and summer, early to midsummer in northern gardens. Each white flower is short-lived, but a stem opens a long succession. The blooms carry a light fragrance.

Detailed Descriptions

Flower Description

white with yellow and violet markings

Foliage Description

dark green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-10 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 Range5.5 - 7.0(Neutral)

357912

Soil Types

loam sand peat

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

2-3 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plants grow in full sun or part shade on moist but free-draining, acidic to neutral soil with added organic matter. They establish from division or pot-grown plants set out in spring, spaced 12-18 inches (30-45 cm) apart. Steady moisture in the growing season supports the foliage, while sharp winter drainage prevents rot. Established clumps tolerate coastal wind and brief drought. Frost below about 20 F (-7 C) damages the evergreen leaves, so the genus suits mild and maritime climates. Clumps are lifted and divided every few years to keep them vigorous.

Pruning

Spent flowering stems are cut back to the base after bloom. Tatty or frost-burned outer leaves are removed in spring as new growth begins. Congested clumps are divided in spring to renew them.

Container Growing

✓ Suitable for container growing

Minimum container size: 3 gallons

✓ Toxicity

Non-toxic