BEAR LAKE – There is a beautiful purple flower along the banks of Bear Lake on the western shoreline that runs from about the Bear Lake Marina to well into Idaho. The purple loosestrife (Lythrum salicaria) can grow to 10 feet tall – depending on conditions – and the purple flower’s stems are about a foot long.
Although the plant’s flowers are pretty to look at, the purple loosestrife is listed as a Class II noxious and invasive weed on the State of Utah Noxious Weed List.
“It’s a semi-aquatic perennial often found along ditch banks and waterways throughout much of the United States, including many areas of Utah,” said Matthew Coombs, Lands Coordinator for the Bear River Area Division of Forestry, Fire & State Lands (FFSL). “While it produces a beautiful pink/purple flower in mid to late summer, it can quickly crowd out native vegetation and degrade the wetland and riparian habitats that are some of the most biologically diverse and productive components of our ecosystem.”
The plant is native to Europe and Asia but was first discovered in the United States in Lake Ontario as early as 1869. It is commonly believed the species was unintentionally introduced to the United States’ by way of the Great Lakes through contaminated solid cargo ship ballast as well as through the deliberate importation of seeds
Coombs said they have been actively treating purple loosestrife at Bear Lake since finding it about six years ago. FFSL invasive weed specialists are using an integrated control strategy that, in this case, includes chemical, mechanical (hand-pulling) and biological controls.
“Some of the challenges are accessing some of these areas for chemical treatments (too shallow from a boat and difficult to get other equipment through wetland areas and soft soils without crossing private property),” he said. “Biological controls have been very successful in many parts of the country, and we have been working to establish populations of Galerucella beetles at Bear Lake as part of our overall control strategy.”
Hand pulling the weeds is a viable option in some areas where there are soft or sandy soils and it is important to make sure all plant parts are placed into a plastic garbage bag for disposal – but can be very labor intensive.
“The public can always help with the management of noxious and invasive species by becoming familiar with how to identify them, reporting them if found, and taking measures to avoid spreading them to other locations,” he said. “Specifically for purple loosestrife or other noxious and invasive species at Bear Lake, adjacent landowners and recreational users can report findings directly to me.”
Coombs said rather than have people using unauthorized chemicals along the shoreline he would be happy to send his staff to treat noxious and invasive species whenever possible.
“Adjacent landowners that are willing to allow us to access these areas from their upland properties could be particularly helpful in this case,” he said.
Bear Lake is not the only place where the invasive species are found. They have also been identified along the Bear River in Cache and Box Elder counties. Both counties are working with FFSL to get rid of the purple loosestrife.