Periwinkle is an invasive plant species that grows along the ground, creating dense carpets that cover everything including native plants and trees. Periwinkle prefers areas with moist soil and only partial sun, and is found on forest floors, in gardens as ground cover, on roadsides, riverbanks and cemeteries.
Impact on Communities and Native Species
Once Periwinkle is established in an ecosystem, it smothers native species. It forms dense strands that envelop all other ground cover around it. This carpet of Periwinkle can also prevent tree saplings and shrubs from growing by blocking out light. The loss of native tree and plant species on stream banks where Periwinkle grows can lead to erosion, as well as the loss of native biodiversity.
Periwinkle came to British Columbia in the same manner as many other invasive plants: as a garden ornamental. Bright blue or violet flowers, dark leaves and the plants ability to grow in shade make it attractive in the garden. It was first introduced to North America in the 1700s from Eurasia and is now found in southern BC - from southern Vancouver Island and the Gulf Islands to the Lower Mainland. It can still be bought in garden stores as ground cover.
Periwinkle moves from place to place, with unintentional human help, in dumped garden waste or as plant fragments carried along in water. The plant has also been used medicinally and has been cultivated to create teas or pastes.