Acaena novae-zelandiae
biddy-biddy
New Zealand and southeastern Australia
Overview
Acaena novae-zelandiae is a low, mat-forming evergreen perennial 2-4 inches (5-10 cm) tall, spreading by creeping, rooting stems to cover 24-40 inches (60-100 cm) or more. Leaves are pinnate, 1-3 inches (2.5-8 cm) long, with 9-15 toothed leaflets, bronze-green to grey-green and often tinged red. In summer it produces rounded flower heads on short stalks held just above the foliage; the small flowers lack petals and have white stamens. As the heads ripen they form spherical burrs about 0.4-0.8 inch (1-2 cm) across, with red to purplish barbed spines that catch on fur, wool, and clothing and carry the seed long distances. The mat roots as it spreads and stays green through winter in mild climates. It grows on open, well-drained ground and tolerates poor soils, drought, and trampling. The clinging burrs make it a contaminant of wool, and it has naturalized and become invasive in parts of Europe and Australia.
Native Range
Native to New Zealand and southeastern Australia, where it grows in grassland, open scrub, coastal sand, and disturbed ground. Found from sea level to montane elevations on well-drained soils. Naturalized in the British Isles, parts of mainland Europe, and other temperate regions, often spread along paths and dunes by burrs caught on animals and people.Suggested Uses
Grown as ground cover between paving, on banks, and in gravel gardens where a low, drought-tolerant mat is wanted, spaced 12-18 inches (30-45 cm) apart. Used to bind dry, open ground. Its clinging burrs and spreading habit make it difficult to contain near grassland, paths, and grazing land.How to Identify
Appearance
Size & Dimensions
Height2" - 4"
Width/Spread2' - 3'4"
Bloom Information
Flower heads appear from November to February in its native Southern Hemisphere range and June to August in the Northern Hemisphere. The petalless flowers are wind-pollinated and inconspicuous. The heads then ripen into spiny red burrs that persist and cling, spreading seed from late summer into autumn.
Detailed Descriptions
Flower Description
greenish with white stamensFoliage Description
bronze-green to grey-greenGrowing Conditions
Sun Requirements
Requires 5-12 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 to light shade on dry to moderately moist, well-drained soils of low fertility, and tolerates sand, gravel, drought, and foot traffic. Establishes quickly from rooted stems or seed and spreads by stems that root at the nodes to form a dense mat. Tolerates drought once established and stays low and tight in lean, sunny conditions, becoming looser in shade or rich soil. The burrs cling to animals and clothing and spread seed widely, so it can move beyond where it is planted. Few pests trouble it. It is regulated as an invasive weed in some regions.Pruning
Trimming or mowing the mat after flowering removes the spiny burrs and limits self-seeding. Stray rooting stems are pulled to keep the mat within bounds. Plants left to seed spread by burrs into surrounding ground.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
summerfall
Container Growing
✓ Suitable for container growing