Periwinkle
Botanical Name
Vinca major
Family
Apocynaceae (periwinkle)
Where is it originally from?
Mediterranean
What does it look like?
Prostrate, scrambling perennial with short rhizomes and green, hairless, trailing stems (>2m long) that 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) appear from Jan-Dec, but 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?
1. Physical removal (all year round) - Dig out entire plant - Ensure all plant material is disposed of to refuse, burnt or buried deeply to prevent regrowth. Ensure no plant material is left on site.
2. Smothering: use black plastic or weed mat. Cover sites as they are, or rake into big rolls and then cover (6+ months). Hand-remove surviving plants.
3. Foliar spray - Apply herbicide using a knapsack sprayer.
Apply Glyphosate (360 g/L active ingredient) herbicide (20ml/L) plus organosilicone penetrant (2ml/L) to cover entire plant
OR metsulfuron-methyl 600g/kg (0.5g/L) + glyphosate 360g/L (20ml/L) + organosilicone penetrant (2ml/L).
*Note: Overspray will kill other (desirable) plants. Avoid spraying metsulfuron around the root zone of desirable plants.
OR triclopyr herbicide (600g/L active ingredient at a 6ml/L) plus organosilicone penetrant (3ml/L). Triclopyr is 'grass friendly' but overspray will damage clover and other broadleaf plants.
Note: Periwinkle is very difficult to kill. Persistence and repeated control measures may be necessary to control this weed.
CAUTION: When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and directions for the purchase, use and storage of the product, are followed and adhered to.
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. May need spraying for 2-3 years for total control.
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