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Dianella tasmanica

Tasman flax-lily

Asphodelaceae

Southeastern Australia (Tasmania, Victoria, New South Wales)

Attracts Pollinators Drought Tolerant Container Friendly

SunPart Shade – Full Shade

WaterMedium · drought-tolerant

HardinessZones 8–10

Overview

Dianella tasmanica is a clumping evergreen perennial in the Asphodelaceae family, forming tufts of strap-shaped leaves 24-40 inches (60-100 cm) long and about 1 inch (2.5 cm) wide that arch outward from the base. The clump reaches 16-24 inches (40-60 cm) tall in leaf, with branched flowering stems rising to 3-5 feet (0.9-1.5 m). In spring and early summer it carries airy panicles of small nodding blue to violet flowers, each about 0.4-0.6 inch (1-1.5 cm) across with six petals and contrasting bright yellow anthers. The flowers are followed by glossy deep violet-blue berries roughly 0.4 inch (1 cm) long that persist into autumn. It is native to cool, moist forests of southeastern Australia and tolerates more shade and cold than many flax-lilies, withstanding light frost. Established clumps are drought tolerant and spread slowly by rhizomes to form colonies. The leaf margins and midribs are finely toothed and can feel rough.

Native Range

Dianella tasmanica is native to southeastern Australia, including Tasmania, Victoria, and southern New South Wales, where it grows in the understorey of cool, moist eucalypt forests. It is named for Tasmania, part of its natural range.

Suggested Uses

Used as a mass planting, understorey filler, and border edge in shaded and woodland gardens, spaced 18-30 inches (45-75 cm) apart. It also grows in containers and tolerates coastal and urban conditions. The blue flowers and violet berries add colour to low-light areas where flowering plants are limited.

How to Identify

Identified by arching strap-shaped leaves 24-40 inches (60-100 cm) long forming a fountain-like clump, with finely toothed margins that feel rough to the touch. Tall branched stems carry nodding blue-violet flowers with bright yellow anthers, followed by glossy violet-blue berries. The large berry size and forest habitat separate it from smaller-fruited flax-lilies.

Appearance

Size & Dimensions

Height1'4" - 5'

Width/Spread1'8" - 3'

Reaches mature size in approximately 2 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~8 weeks

Spring Summer

Flowering occurs in spring and early summer, roughly September to December in the Southern Hemisphere. The branched stems hold loose sprays of blue-violet flowers that open over several weeks. Violet-blue berries follow and can remain on the stems through autumn.

Detailed Descriptions

Flower Description

Blue to violet

Foliage Description

Green

Growing Conditions

Sun Requirements

SunPartial Shade SunFull Shade

Requires 2-6 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 clay sand

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

Grows in part shade to full shade, and in cooler climates full sun, in moist, humus-rich, well-drained soil with a pH of 5.5-7.0. It tolerates a range of soils including clay and accepts periods of dryness once the clump is established. Light frost is tolerated, and the evergreen foliage holds through winter in mild areas. Clumps are divided in spring to propagate or to control spread. Removing spent flower stems keeps the clump tidy, though the berries are often left for colour.

Pruning

Tired or frost-marked foliage is cut back to the base in late winter, prompting fresh growth. Spent flowering stems are trimmed at the base once the berries finish. Old clumps are lifted and divided every few years to maintain vigour.

Pruning Schedule

winter