The early green in Minnesota woodlands is a welcome sign of spring for many people, but not for John Peterson, who owns 25 acres of forest in Delano.
Peterson knows that much of the green on his forest floor is garlic mustard, and he's been waging an all-out war on the invasive plant for the past five years.
"I never thought a little biennial plant would be such trouble and so hard to get rid of," Peterson said. "It's really murder."
New garlic-mustard patches pop up in late April and early May. It is one of the state's most noxious weeds, and it forms a dense carpet that crowds out tree seedlings and native wildflowers such as bloodroot, lady's slipper, wild ginger and trillium.
Janet Van Sloun, restoration specialist for the city of Minnetonka's natural resources department, said garlic mustard is such a problem because it came from Europe and has no natural predators in the United States to keep it in check.
"Nothing eats it here, no animals, no insects, and it gets into a woodland and it just takes over and spreads incredibly quickly," she said.
Since 2007, Van Sloun has offered spring workshops and trained more than 600 Minnetonka residents in how to identify and remove the plant from their yards. One workshop was held last week, and two more are slated for May 23 and June 12. Van Sloun also works with volunteer groups and individuals to yank the prolific plant at 15 of the city's parks.
Plant hogs light, nutrients
Eli Sagor, University of Minnesota Extension educator, said garlic mustard is widespread in the southern half of the state and is spreading north, especially in the shady, moist conditions of hardwood forests and other places with trees: flood plains, trails and creek corridors. Garlic mustard and buckthorn — a non-native woody invader — are probably the two biggest plants jeopardizing healthy forests, he said.