My experience with garlic mustard goes back to 1970 when my bride and I honeymooned in Peninsula State Park. The park naturalist gave us a few plastic bags about the size of the plastic bags you get in the grocery store if you are not ecologically minded enough to bring your own reusable bags. We dutifully pulled the invasive at our campsite and felt proud when we deposited a bag or two at our campsite post where park personnel would collect them.
I learned the infestation had started a few years earlier along the Sunset Bike Trail in the area between the North Nicolet Bay campground and the Welcker’s Point Campground. The small patch, just a few feet in diameter, spread rapidly. Bicycle tires picked up the seeds and scattered them down the trail. Hikers would step off the trail to let bicycles by. Garlic mustard seeds would stick to their boots. Within a decade, this small patch had spread to hundreds of acres in the park. The small bags I received in 1970 quickly morphed into 30 gallon trash bags.
My wife and I were instrumental in starting a Friends Group at Peninsula State Park in 2006. We recruited a good cross section of people who resided in the area, loved nature, loved birds, loved to hike, bicycle and cross country ski. Most of all, they loved the park. One of these people was Bob Bultman, the head of the Door County Invasive Species Team. Bob was enthusiastic. He wooed me with his wisdom, “Norm, we aren’t going to win this war without chemicals.” Bob made it sound easy. Garlic mustard remains green throughout the winter. All you had to do was hit it with Glyphosate (Roundup) early in the spring before other “good” vegetation emerged. Piece of cake. We went to see Tom Blackwood, park superintendent, with our plan. I can still hear Tom’s voice booming in the park office, “Norm, that stuff kills everything!” Bob and I retreated.
Bob introduced me to a propane torch. It worked well, on small first year plants in areas where there was no litter with hundreds of small, first year, single leaf sprouts the size of a letter on this page. A quick swipe with the torch would mean instant death to thousands of plants. The problem was with second year plants hidden in heavy litter. But we convinced Tom to allow us to conduct a demonstration. It was dry. There was abundant ground litter. I brought two backpack sprayers full of water and followed Bob while he torched garlic mustard. Of course, Bob’s torch started numerous fires I quickly put out. I described Tom’s expression at the Friends Annual Meeting that fall. I held two large white paper plates over my eyes. Tom didn’t give us permission to use the torches, but he did say we could use roundup.
I began some experiments years ago on a small 100 X 100 foot wooded valley on our property in Orfordville infested with garlic mustard. I sprayed the valley in early spring with roundup. I killed the mustard, but I also killed the grass. The next spring, following some heavy rains, I had a 100 foot long gully. I switched to 2, 4-D which does not kill the grasses. After a few years, when the population of garlic mustard started to diminish, I switched to hand pulling. I did this diligently for years. This spring, after years of control efforts, the valley sported another good crop of mustard.
And what of Peninsula State Park? The Friends had success in two small areas where ample volunteer labor could do the job – an acre just north of the lighthouse, a small triangle formed by the intersection of Skyline and Shore Roads. Some small areas where the Dwarf Lake Iris was threatened with garlic mustard have been protected, but acres of infestation remain. As an April Fools’ joke I once told the Friends that we were financing research to develop a strain of garlic mustard that would pull itself. Tom Blackwood told me that his observations were that the mustard in the area of the initial infestation was dying out. I’ve been watching it and I believe Tom is right. For some reason, garlic mustard is not the scourge in Europe from whence it originated. Perhaps it thrives while establishing itself or in response to eradication efforts?
Here is what the Door County Invasive Species Team is saying now. Invasive species have been divided into three tiers. Tier 1 is high priority and contains species that exist only in isolated or scattered populations, i.e. control is possible and further spread of the invasive can be prevented. Tier 2 is mid priority containing species that are more widespread than Tier 1, but at levels still considered manageable. Tier 3 is low priority and includes species considered very widespread making control efforts extremely difficult and reoccurrence likely. This is the category where garlic mustard is listed. Here is a link to the Door County Invasive Species Strategic Plan:
Click HERE to view the Strategic Plan.
Years ago, I planted lilacs along our driveway. They are now eight feet tall and occupy a footprint about six feet in diameter dominated by numerous good sized stems. This year, most have a good crop of garlic mustard covering the bare ground in the footprint. The lilacs exhibiting the heaviest garlic mustard populations are those with a bird nest in the shrub.
Years ago, I called a truce with my dandelions. I figured it was not worth the time and effort to keep those “pretty yellow flowers” out of my lawn. I just made a similar truce with my garlic mustard. Charles Darwin taught us about the survival of the fittest. Who am I to argue with Mother Nature?