Blue Periwinkle
(Vinca or Vinca major)
This is a Blue Mountains Local Priority Weed. There are infestations in Mount Wilson bushland where it has escaped from gardens.
Type of weed: Vine or scrambler
Flower colour(s): Blue-purple, White
Flowering Months: October to February
Description
Periwinkle is a vine that has a woody crown bearing runners up to 1 m long. The root system is hardy and fibrous, forming a mat 15–30 cm deep in the soil.
Leaves are large (15–60 mm long, 14–45 mm wide) with stalks and opposite. Each pair of leaves is generally at right angles to those above and below. The upper leaf surface is glossy and there are generally very short hairs along the leaf margins.
Flowers are large, 30–40 mm across and blue-purple or sometimes white, with five lobes from a basal tube 16–17 mm long. They are borne on upright stems to 50 cm long mainly in spring to summer.
Fruits (follicles) are 35–40 mm long, tapered at both ends and usually paired.
Periwinkle mostly reproduces vegetatively, but some produce viable seeds. Infestation most often comes from dumped garden waste and garden escapees. The overall impact on bushland and gardens is that the plant covers the ground smothering all other plants and therefore impedes the growth of other plants and the regeneration of native vegetation.
Control: Manual removal
Move leaf litter away from base of plant. Dig down next to the stem, remove the plant completely, taking care not to break or drop the stems. Dispose of all plant material in the council green waste bin.
Control: Chemical control
Spray with herbicide. The approved herbicides for this weed include Fluroxypyr, Glyphosate, Metsulfuron methyl.
Control: Scrape and paint
Use a knife to scrape long gashes along stem and immediately paint with herbicide
Considerations:
Very small patches (less than 1 m square) can be dug up. Follow-up treatments will be required.
Stem and root fragments can re-sprout, so all plant material needs to be removed or spread out to dry on the ground.
Spraying dense areas of Vinca can be effective if no native plants are present. Use a weak solution of herbicide with a surfactant to thoroughly wet all foliage and stems.
Resources
For further information on the management of weeds on your property.