Minor Plant, Major Annoyance
Posted on October 30, 2024
As the saying goes, “It’s the little things,” and lesser periwinkle (Vinca minor) is no exception. This little plant is causing COL staff a major headache on multiple preserves, namely at Robinson Woods and Flynn Woods.
The Problem
You might already be familiar with Vinca. It was originally brought over from Europe for landscaping, and it is a popular addition to yards and gardens to this day. Some people even mistake it for a native spring ephemeral—it produces tiny, pinwheel-like purple flowers in March or April. While not technically classified as an invasive species in Michigan, Vinca minor is a non-native species with a tendency to take over areas of forest floors and crowd out natives.
In Robinson Woods, you can find spring ephemerals like prairie trillium trying to survive in the dense layer of Vinca. And trust us, it would be way cooler to have a blanket of varied wildflowers greeting hikers at the trailhead each spring instead of that big ol’ patch of Vinca.
Earlier this year, COL staff, volunteers, and Mighty Acorns students hand-pulled countless bags of this viney plant on multiple occasions (maybe you even helped us). While we certainly cleared a lot, this control method was time-consuming and the jury is still out on what percentage will grow back. Plus, Vinca isn't our TOP priority. Like we mentioned earlier, it's not officially considered an invasive species, but there are still better, native options that would be more beneficial to wildlife.
The Project
To save staff and volunteer time, our field crew has decided to do a science experiment to determine the most effective treatment method. Over the next six months, our crew will treat several test plots of Vinca using a variety of herbicide and surfactant mixtures at three points in the year: fall, winter, and spring. Environmental factors like temperature, humidity, wind speed, and cloud cover will be noted at the time of each treatment.
They will revisit the test plots one month after the initial application and then again the following season to assess what percentage of Vinca was affected by each unique mixture. They'll also monitor the presence of spring ephemerals along the way.
Recently, our crew finished the fall application. Five 2m x 2m test plots were treated in the initial application (boundaries are marked by the red pin flags):
There's obviously nothing to report yet, but we're looking forward to—hopefully—drawing some conclusions about both WHEN and HOW we can most effectively handle this Vinca. Stay tuned for more updates over the next six months as we monitor our progress and photograph the results...because science is fun!
