Apocynaceae (periwinkle) family
Where is it originally from?
What does it look like?
Prostrate, scrambling perennial with short rhizomes and green, hairless, trailing stems that can grow up to 2+ m long and take root where they come in contact with the soil. Glossy dark green or occasionally variegated (green and white) leaves (4-10 x 3-7 cm) are in opposite pairs on the stem. Solitary, blue-violet, 5-petalled flowers (up to 4-5 cm in diameter) are produced from January to December. Seed is not usually produced.
Are there any similar species?
Lesser periwinkle (Vinca minor) is similar, but has smaller leaves (2-5 x 1-2 cm) and flowers are usually doubles that are half the size of those of V. major.
Why is it weedy?
Creeping, layering habit allows it to form dense, long-lived stands. Tolerates semi-shade and full sun, salt, most soils, wet or drought conditions, hot and cold temperatures, heavy damage and grazing.
How does it spread?
Rhizome and stem fragments and occasionally seeds are spread through dumped greenwaste and soil, and occasionally by water movement. Sources of infestation include old established sites, such as old homestead gardens, cemeteries, woodlots, and farms.
What damage does it do?
Smothers ground in open or shady conditions, prevents the seedlings of native species from establishing, and opening up habitats so that they are more vulnerable to weedy vines, grasses and so on.
Which habitats is it likely to invade?
Margins of disturbed bush and shrublands, streamsides, coastline, fernland, and rocky and bare land.
What can I do to get rid of it?
Extremely difficult to kill.
1. Dig out very small sites. Dispose of plant material at a refuse transfer station or burn. Check for regrowth.
2. Spray (all year round): glyphosate (20ml/L + penetrant). Follow up on resprouting pieces with (30ml/L) mix. Requires constant follow up. Apply twice a year, in spring and in autumn. Treatment is required for three or more years.
3. Spray (all year round): 20ml glyphosate + 1g metsulfuron-methyl 600g/kg per 10L. Avoid use within drip line of susceptible species.
4. Mowing: For level, easily accessed land, mow with lawnmower on very low setting, 2-3 times a year. As it regrows, follow up by grubbing remaining roots with grubber or shovel. Leave on site to rot down. Takes 1-2 years to eradicate.
5. Smothering: use black plastic or weedmat. Cover sites as they are, or rake into big rolls and then cover (6+ months). Hand-remove surviving plants.
What can I do to stop it coming back?
Follow up control methods when foliage is still small to prevent recovery of root reserves - usually means four times annually.