Myoporum insulare
common boobialla
Overview
Myoporum insulare is an evergreen shrub to small tree reaching 6-20 feet (1.8-6 m) tall with a similar spread, forming a dense rounded to spreading canopy. Stems are smooth and green when young, becoming grey-barked with age. Leaves are alternate, fleshy, oblanceolate, 2-3.5 inches (5-9 cm) long and 0.4-0.8 inch (10-20 mm) wide, bright green with translucent oil dots and finely toothed margins near the tip. White flowers 0.3 inch (6-8 mm) across, marked with small purple spots in the throat, appear in clusters of 3-8 in the leaf axils. Globular fleshy drupes 0.2-0.35 inch (6-9 mm) wide follow, ripening from green to purple-black. Growth is rapid in coastal sands, with plants reaching full size in 4-6 years. The species tolerates salt spray, wind, and sandy alkaline soils. Foliage contains hepatotoxic furanosesquiterpenoid oils that cause liver damage in grazing livestock. In heavy or poorly drained soils the root system stays shallow and plants can be windthrown.
Native Range
Native to the southern coastline of Australia, including coastal South Australia, Victoria, Tasmania, southern New South Wales, and southwestern Western Australia. Grows on coastal dunes, clifftops, and limestone headlands, often within reach of salt spray at elevations below 330 feet (100 m).Suggested Uses
Planted as a coastal hedge, windbreak, or sand-binding screen, spaced 5-8 feet (1.5-2.4 m) apart. Used in low-maintenance seaside gardens and for dune stabilisation. The shallow roots and brittle older wood limit its use close to paths or paving.How to Identify
Appearance
Size & Dimensions
Height6' - 20'
Width/Spread6' - 15'
Reaches mature size in approximately 6 years
Bloom Information
Flowers mainly from late winter through summer, roughly August to January in its native range. Individual flower clusters last 2-3 weeks, with scattered flowering possible year-round in frost-free coastal sites. Fruit set follows over 6-10 weeks. Cooler inland conditions delay and shorten the flowering period.
Detailed Descriptions
Flower Description
white with purple spotsFoliage Description
bright greenGrowing Conditions
Sun Requirements
Requires 6-10 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
Care & Maintenance
Care Guide
Establishes quickly in free-draining sandy or limestone soils with weekly water through the first summer; established plants grow on rainfall alone in coastal climates. The species tolerates salt-laden wind, suiting it to exposed seaside positions. It grows in full sun to light shade, becoming open and sparse in dense shade. Root systems are shallow, so plants in heavy soils or windy inland sites can be unstable. Scale insects and sooty mould occur in still, humid conditions. Lifespan is typically 15-30 years in cultivation.Pruning
Responds to hard pruning by reshooting from old wood, allowing it to be held as a clipped hedge or windbreak. Trimming after the main flush of flowering, removing up to one third of the canopy, keeps growth dense. Untrimmed plants become open and small-tree-like with bare lower stems.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
summer
Container Growing
✓ Suitable for container growing
Minimum container size: 10 gallons