Clusiaceae (St John’s wort) family
Also known as
Where is it originally from?
South and Western Europe
What does it look like?
Small, perennial, hairless, semi-evergreen shrub (<1.5 m) with fibrous roots and no rhizomes. Stems are semi-woody, winged, usually reddish, and often lax. Fragrant stalkless ovalish leaves (35-100 x 25-50 mm) are opposite, usually bluish underneath and usually turn red in autumn. Yellow, 5-petalled flowers (15-25 mm diameter, Nov-Feb) with long stamens are followed by round red berries (1 cm diameter) that ripen to black and contain cylindrical or curved seeds (9-10 mm long).
Are there any similar species?
Rose of Sharon (Hypericum calycinum) has 7-9 cm diameter flowers, dry fruits, 4-angled stems and rhizomes. H x inodorum has fleshy fruit.
Why is it weedy?
Produces many, long-lived, well dispersed seed. Tolerates semi-shade, hot or cold temperatures, high to moderate rainfall, damage and grazing (rare).
How does it spread?
Birds and possibly possums, and soil and water movement. Common seed sources include roadsides, farms, waste land, old gardens and cemeteries.
What damage does it do?
Invades regenerating sites, forms dense stands, and prevents establishment of native plant seedlings. Usually succeeded by taller vegetation, but is persistent in shorter habitats.
Which habitats is it likely to invade?
Disturbed forest and shrubland, low-growing habitats, tussockland, bare land, and rocklands. Usually high rainfall areas.
What can I do to get rid of it?
1. Dig out small spots. Leave on site to rot down.
2. Cut down and paint stump (spring-summer only): metsulfuron-methyl 600g/kg (5g/L).
3. Spray (Nov-Jan): glyphosate (10ml/L + penetrant) or metsulfuron-methyl 600g/kg (5g/10L) or triclopyr 600 EC (50ml/10L) or triclopyr 120g/L (250ml/10L).
What can I do to stop it coming back?
Reseeds onto bared sites. Occasionally resprouts from roots after poor spray kill. Difficult to kill, herbicide timing important. In regenerating tall forest, may be left to natural succession. Replant bared sites densely to minimise seedlings.