TRAVERSE CITY — Local environmental officials have a thorn in their side — literally.
A popular decorative shrub called Japanese barberry comes with sharp thorns and dense foliage, often in shades of red and purple, as well as green. The problem is it's an invasive plant that grows at voracious rates, leaping from original landscaping beds and spreading into natural areas.
"Japanese barberry is a particularly troublesome ornamental because of how desirable it is as a deer-resistant plant," said Emily Cook, outreach specialist for the Northwest Michigan Invasive Species Network. "It's covered in thorns making it nearly impossible to consume and on top of that, barberry endures a range of conditions including drought and cold temperatures."
Continued demand for this plant in local landscaping makes management of the invasive species in the wild a challenge, she said.
"We can continue to treat populations that we have found spreading into nearby natural areas, but as long as new plants are being sold and installed, and birds are spreading the berries, it becomes a perfect 'one step forward, two steps backward' situation," Cook said.
Environmental officials are finding thick growth of Japanese barberry taking over and completely crowding out native woodland plants. Beyond that, studies have shown the plant is the ideal habitat for black-legged ticks, which often carry Lyme disease.
"Areas dense with barberry contain up to 10 times as many ticks than areas without the plant," Cook said.
Japanese barberry was first introduced to North America as an ornamental — common among invasive plants — and has become more commonly used in recent decades.
The nonprofit network will offer area landowners an opportunity to trade in their Japanese barberry shrubs for a non-invasive alternative. Participants can bring their removed barberry plants for proper disposal and in exchange receive a $5 coupon, up to $50 total.
The coupons can be used at plant nurseries across the region which are enrolled in the organization's Go Beyond Beauty program, which involves businesses committed not to sell high-risk invasive ornamental species and instead encourage the use of native plants in landscaping.
"Because deer-resistant plants are important here in northern Michigan, (Northwest Michigan Invasive Species Network) is also happy to provide a list of native recommendations that are less likely to get munched," Cook said. "Some even look similar to barberry."
Tom Brodhagen, owner of Greystone Gardens in Empire, said there are a number of native shrubs which deer tend to avoid, including Kalm's St. John's wort, arrowwood vibernum and bayberry.
Decades of landscaping with invasive plants and flowers across the region created what Brodhagen described as a "food desert" for pollinators and other insects.
"The native plants tend to do very well, as they developed in the areas we are in," he said. "By removing the native plants out of that ecosystem, we have really modified the environment for the wildlife."
That impact then travels up the food chain, Brodhagen said, impacting not only insects, but also birds, reptiles and mammals.
The replacement of Japanese barberry with native plants that support the local environment is a good way to break that trend, Cook said.
The first Japanese barberry trade-up day is set for June 7 at Boardman River Nature Center in Traverse City, with a second scheduled for June 22 at Grow Benzie in Benzonia. Registration is required and available at www.habitatmatters.org online.
Funding for the program is provided through grants from the Michigan Invasive Species Grant Program and the Great Lakes Restorative Initiative, Cook said.
The Northwest Michigan Invasive Species Network is an association of more than 40 organizations dedicated to the management of invasive plants and educational outreach efforts. The agency serves Benzie, Grand Traverse, Leelanau and Manistee counties.
Want to go?
What: Japanese barberry trade-up day
Where: Boardman River Nature Center, 1450 Cass Road, Traverse City
When: 2-6 p.m. June 7
How: Required registration at www.habitatmatters.org
More details: Call 231-941-0960, ext. 20, or send email to firstname.lastname@example.org
Source: Northwest Michigan Invasive Species Network