Xanthorrhoea preissii
Balga
Overview
Xanthorrhoea preissii is a slow-growing evergreen grass tree that forms a thick, blackened trunk topped with a dense crown of long, grass-like leaves. The trunk reaches 3-15 feet (1-4.5 m) tall over many decades, often less than 0.4 inch (1 cm) of height gain per year, and the leaves are stiff, narrow, and 16-40 inches (40-100 cm) long, arching out and down from the crown. Old leaves bend back and skirt the trunk as they die. After fire or in some seasons the plant sends up a single tall flower spike 6-13 feet (1.8-4 m) long, the upper half densely packed with small cream flowers. Black resin coats the leaf bases and trunk. The plant resprouts from its base after fire, which often triggers heavy flowering. Growth is slow throughout, and the trunk forms only after many years.
Native Range
Native to south-western Western Australia. Grows in jarrah and wandoo forest, woodland, and heath on sandy and gravelly soils, in a climate of wet winters and dry summers.Suggested Uses
Grown as a long-lived structural plant in native, dry, and gravel gardens on sandy soils, spaced well apart to suit its eventual size. It tolerates heat, drought, and low-nutrient ground where many plants fail. Large transplanted specimens are sometimes used in landscaping, though establishment is slow and uncertain.How to Identify
Appearance
Size & Dimensions
Height3' - 15'
Width/Spread3' - 6'
Reaches mature size in approximately 30 years
Bloom Information
Flowering is irregular and often follows summer fire, with spikes appearing mainly from late winter into spring. The cream flowers open in waves along the spike over several weeks, starting on the side that faced the warmest sun. Many years can pass between flowerings on an individual plant.
Detailed Descriptions
Foliage Description
green to grey-greenGrowing Conditions
Sun Requirements
Requires 6-12 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 in well-drained sandy or gravelly soil with low fertility, matching its dry-summer habitat. Water sparingly, as the plant tolerates long dry periods and rots in wet or rich soil. It resents root disturbance, and transplanting large specimens often fails because of the deep, fungus-linked root system. Phosphorus-rich fertilisers can harm the roots. Growth is slow, with the trunk taking decades to form. Crown rot from the soil organism Phytophthora is the main threat in moist or disturbed ground.Pruning
Pruning is limited to removing spent flower spikes and trimming the dead leaf skirt if desired, though the skirt protects the trunk. Green leaves are left uncut, as the single crown does not reshoot if cut off. Old flower spikes can be cut once seed has dropped.Container Growing
✓ Suitable for container growing
Minimum container size: 10 gallons