Periwinkle difficult to control, quick to dominate
Invasive Plant of the Month Feature
Periwinkle is difficult to control, quick to dominate
By Helen Varekamp and Renee Sandelowsky
Renee Sandelowsky and Helen Varekamp are Bayfield residents and local volunteers. They are writing a monthly series of articles, for the Canadian Coalition for Invasive Plant Regulation, about the benefits of planting native species of plants and removing invasive species. This month (March 2025), their focus is on Periwinkle – Vinca minor.
Invasive plants are plants introduced from other parts of the world and known to have detrimental impacts on human health, the environment, and the economy.
As consumers, we assume garden centres would never sell plants that can do harm. Sadly, this assumption is not always true. The sale of many high-risk invasive plants is not regulated in Ontario. Some garden centres may sell invasive plants, knowingly or unknowingly.
Some high-risk invasive species on the Ontario Auditor General’s Do Not Plant or Sell List include: Periwinkle; Burning Bush; English Ivy; Amur Maple; Lily of the Valley; Japanese Barberry; Pachysandra; and Japanese Honeysuckle.
The next time you go to a garden centre, consider asking if the plant you are buying is invasive or not. If it is, ask why it’s not labelled. As a consumer, we all have a right to know what we are purchasing.
Focus on Periwinkle – Vinca minor
Periwinkle has become a major issue, in the Bayfield area and beyond, taking over large areas of natural habitat. This plant thrives in shaded, moist conditions such as forested areas and along waterways. This invasive plant can even grow in dry shade.
Periwinkle can reproduce through underground roots, and any fragment of its stem, transported via water, wind or animals. This makes it difficult to control and quick to dominate. Periwinkle spreads forming dense mats that exclude other plants including Trilliums and tree seedlings.
Despite its harmful impacts, Periwinkle remains one of the Top Six invasive species still sold in garden centres. Stop purchasing, sharing or trading this plant to help prevent further ecological damage.
HOW TO MANAGE PERIWINKLE
Managing Periwinkle is challenging but achievable with persistence and a multi-step approach. Your control efforts should focus on preventing the spread of this invasive species. Focus on edges first, reversing the invasion front.
Manual Removal:
Removal is most effective when the soil is moist, especially in clay soils. Work on a small section at a time. For sprawling runners, use a rake to lift them from the ground and mow the area to help contain the spread. Dig out plants, ensuring roots are fully removed. Place plants in black plastic bags and dispose in garbage, never in the compost or municipal green waste.
Repeat inspection and removal of Periwinkle regularly for at least a year.
Smothering:
Cut the Periwinkle down and cover smaller infestations with tarps or cardboard or a thick layer of mulch to block sunlight and water. This can be started any time of year and the process can take up to two years to complete.
Herbicide Treatment:
Use herbicides only as a last resort, following local regulations to minimize environmental harm.
After removal, replant the area with regionally appropriate native plants. This step is essential to prevent reinfestation and to restore ecosystem health. Native plants will also attract pollinators and wildlife, improving biodiversity in your garden.
A good choice, as an alternative, would be Wild Geranium – Geranium Maculatum.
LEARN MORE AND TAKE ACTION
Education is key to combating invasive plants. Learn to identify invasive species and choose native or non-invasive alternatives for your garden. Focus on managing one or two invasive plants at a time and be patient — successful eradication takes time and persistence.
To learn more, visit:
- Ontario Invasive Plant Council
- Canadian Coalition for Invasive Plant Regulation
- Grow Me Instead Guide