General: Large Periwinkle is an evergreen to semi-evergreen trailing perennial.
Flowers: Pale blue to lavender, up to 3 cm wide. There is one flower per stem, which consists of 5 petals arranged pinwheel-style. Periwinkle blooms in late spring or early summer.
Stem: Evergreen, tender stems, 25 – 50cm long, branched out to form a trailing or spreading groundcover. Stems contain a milky latex.
Leaves: Shiny, dark green and opposite, 3 – 9 cm long. Shape is oval or heart shaped.
Seeds: Grow in 3-5 cm long, cylindrical pods.
Small Periwinkle (Vinca minor): There are two kinds of periwinkle, small (Vinca minor) and large (Vinca major). As the name suggests, the major difference between the two is the size of their leaves. V. major has slightly larger and broader leaves, that are in an oval or heart shape. V. minor has smaller, elongated leaves that are lance-shaped.
Learn more about the differences between Small and Large Periwinkle here.
Madagascar Periwinkle (Catharantheus roseus): This plant is from the same family (Apocynaceae) as Small and Large Periwinkle, and has similar-looking leaves and flowers. This plant can be distinguished from other periwinkle species by its pink flowers, and more upright stems. It typically grows in hotter climates, such as Madagascar or the southern US, and is not found in the Sea to Sky.
Habitat and Origin
Originally native to Eurasia and northern Africa, Large Periwinkle was introduced to North America in the 1700’s as an ornamental.
Large Periwinkle thrives in a variety of soils, from well-drained to moist and from sand to clay. As it tends to prefer partially-shaded areas, Large Periwinkle commonly invades forested and riparian areas.
Propagation & Vectors of Spread
Large Periwinkle reproduces primarily vegetatively; propagation by seed is possible, though seeds may not be viable.
When Large Periwinkle spreads vegetatively, it does so through its stems rooting at the nodes as well as by spreading underground stems, called stolons.
Large Periwinkle’s main vector of spread is the horticulture trade, as it is widely sold in garden centres and nurseries as a shade-loving groundcover. Moreover, improper disposal by gardeners can aid its spread.
Large Periwinkle also spreads by stems and stolons (underground stems) rooting at the nodes. Lastly, the seeds can also be dispersed in water.
Ecological and Health Impacts
- Crowds out and discourages the growth of native plants by forming extensive mats along the forest floor (reduces biodiversity).
- Can lead to erosion when it grows on riverbanks as it outcompetes native, deeper-rooted plants.
- Periwinkle is allelopathic: it can inhibit the germination and seedling growth in plants of other species which may add to its competitive advantage.
- Can negatively impact animals utilizing riparian corridors by reducing the amount of forage available on riverbanks.
- Toxic to humans and animals if ingested.
What Can I Do?
Large Periwinkle is not yet found in the Sea to Sky Region, so PREVENTION is key.
Learn to identify Large Periwinkle: use the images presented in this profile page to learn how to identify this plant.
What to do if you spot it: You can report any Periwinkle sighting by clicking here.
- Regularly monitor properties for infestations.
- Be PlantWise: avoid planting Large Periwinkle, no matter how well-contained its enclosure might seem.
- Ensure soil and gravel are uncontaminated before transport.
- Minimize soil disturbances and use seed mixes, or other non-invasive ground cover plants to re-vegetate exposed soil and resist invasion.
- Ensure plants (particularly flowering heads or root fragments) are bagged or covered to prevent spread during transport to designated disposal sites (e.g. landfill).
- Don’t unload, park, or store equipment or vehicles in infested areas; remove plant material from any equipment, vehicles, or clothing used in such areas, and wash equipment and vehicles before leaving infested areas.
- DO NOT COMPOST!
- Hand-pull periwinkle repeatedly as it appears; persistence is key.
- Try to remove all of the plant and its roots, and dispose of plant material.
- Apply mulch to bare soil, or re-plant with non-invasive species after removal.
- ‘Matting’ small infestations (covering with tarps) for 4-6 months after they have been pulled may also be effective.
- Foliar application of glyphosate to growing plants (late summer – early fall) can be effective, especially as a follow-up to mechanical methods.
- Other herbicides including triclopyr (applied in spring) and imazapyr (applied in late summer to early fall) can also be effective.
- We recommend that any herbicide application is carried out by a person holding a valid BC Pesticide Applicator Certificate. Before selecting and applying herbicides, you must review and follow herbicide labels and application rates; municipal, regional, provincial and federal laws and regulations; species-specific treatment recommendations, and site-specific goals and objectives.
While there are no biocontrol agents currently available in BC, Large Periwinkle is susceptible to fungal foliar disease.
- California Invasive Plant Council, Vinca major, https://www.cal-ipc.org/plants/profile/vinca-major-profile
- Central Kootenay Invasive Species Society, Periwinkle, https://ckiss.ca/species/periwinkle/
- Coastal Invasive Species Committee, Periwinkle Species, https://www.coastalisc.com/periwinkle-species/
- Evergreen, Common Periwinkle Invasive Plant Profile, https://www.evergreen.ca/downloads/pdfs/Invasive-Plant-Profile-Periwinkle.pdf
- Global Invasive Species Database, Vinca major, http://www.iucngisd.org/gisd/pdf.php?sc=487
- Invasive Species Compendium, Vinca minor, https://www.cabi.org/isc/datasheet/56403
- Invasive Species Council of BC, Common Periwinkle, https://bcinvasives.ca/invasives/common-periwinkle/
- NatureGate, Lesser Periwinkle, http://www.luontoportti.com/suomi/en/kukkakasvit/lesser-periwinkle
- Washington State Noxious Weed Control Board, Periwinkle, https://www.nwcb.wa.gov/weeds/periwinkle
- Whatcom County Noxious Weeds Control Board, Periwinkle, https://www.whatcomcounty.us/DocumentCenter/View/27176/Periwinkle