Michigan Has a Tiny Fighter Against A Ferocious Invasive Plant
A plant that was brought to North America as a culinary/medicinal herb, in the 1800s, has become an invasive species that quickly overtake native plants and spreads like wildfire. We’re talking about invasive Garlic mustard.
It’s a pesky plant that shoots up during early spring, and it grows just about anywhere, in any type of soil. It will put down roots in the sun, shade, and moist or dry soils.
Besides spreading quickly, another weapon that it has in its arsenal is allelopathy; the ability to release chemicals that can limit or prevent the growth of other plants. Early settlers from Europe may have had good intentions, using the garlic flavor to season soups, meats, and sauces, but by 2023, it is overtaking any open patch of ground
First-year plants appear as ground cover with serrated, round leaves and are called basal rosettes. The second year produces a plant with 1-4 ft. stems, with clusters of tiny white, four-petaled flowers. The plants can produce hundreds of seeds that spread easily.
However, now for the good news. A small garlic mustard aphid has just been discovered, by accident. Rebecah Troutman, a natural areas biologist at Holden Forests and Gardens, in Ohio, was pulling garlic mustard plants when she noticed a plant covered with tiny insects.
It was the first official sighting of the European aphid in the U.S., sometimes called the “grenade” aphid because of the raised patterns on its greyish-green back. They actually do look like grenades, and they do a great job of wiping out garlic mustard plants, by sucking sap from the plant.
Since the discovery of these little suckers, conservationists have noticed isolated populations in Connecticut, Massachusetts, Michigan, Minnesota, Ohio, and Wisconsin. As a result, plants are becoming fewer and shorter with fewer seed pods, which are now becoming twisted.
The Michigan Department of Natural Resources has a suggestion for people who are disposing of garlic mustard plants that may have plagued their yards. Double-bag all plant material and place bags in sunlight for a few days to allow plants to decompose before disposal.