Xanthorrhoea semiplana
tufted grass-tree
Overview
Xanthorrhoea semiplana is a slow-growing perennial grass-tree forming a dense tuft of long, narrow, grass-like leaves from a short or largely underground stem, with the leaf crown reaching 2-4 feet (0.6-1.2 m) high and across. The leaves are stiff, flat to slightly angled in cross-section, 1.5-3 feet (45-90 cm) long, and grey-green to green. After fire or in mature plants, a tall flower spike develops: a dense cylindrical brush of small cream flowers, 1-3 feet (30-90 cm) long, on a bare scape that lifts it well above the foliage. Flowering is irregular and often follows fire. The small flowers produce nectar and are followed by woody capsules. Growth is very slow, with stems extending only a fraction of an inch per year, so large plants are many decades old. The dense leaf base and slow growth make established plants difficult to transplant. Old leaves persist as a skirt around the base.
Native Range
Native to South Australia, including the Mount Lofty Ranges, Kangaroo Island, and the Fleurieu and Yorke Peninsulas. Grows in heath, mallee, and open woodland on sandy and lateritic well-drained soils.Suggested Uses
Used as a slow-growing feature plant in native, low-water, and fire-adapted gardens, spaced 3-6 feet (1-1.8 m) apart. Grown in large containers of free-draining mix when young. The very slow growth and sensitivity to disturbance limit its use to permanent positions.How to Identify
Appearance
Size & Dimensions
Height2' - 4'
Width/Spread2' - 4'
Reaches mature size in approximately 20 years
Colors
Bloom Information
Flowering is irregular and often triggered by fire, occurring mainly in spring and summer (September to January in its native range). The cylindrical flower spike opens its small cream flowers in sections over several weeks. Many years can pass between flowering events on a single plant.
Detailed Descriptions
Foliage Description
grey-green to greenGrowing Conditions
Sun Requirements
Requires 5-9 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
Care & Maintenance
Care Guide
Grows in full sun to light shade in sandy or gravelly, sharply drained soils of low fertility. Water lightly during establishment; established plants are highly drought tolerant and decline in rich or wet soils. Tolerates moderate frost and recovers from fire by reshooting from the base. Growth is very slow, so plants change little in size over many years. Root disturbance and overwatering are the main causes of decline, and plants are susceptible to root-rot fungi in damp soils. Established plants are difficult to move and rarely transplant successfully.Pruning
No routine pruning is required. Dead outer leaves can be removed to expose the stem, though many plants are left with the natural leaf skirt. Spent flower spikes can be cut once seed has shed.Container Growing
✓ Suitable for container growing
Minimum container size: 5 gallons