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2011
Purple Loostrife
Loosestrife becomes dominant plant in Big Cove
Purple loosestrife is an invasive plant native to Europe and Asia which infests wetlands, wet meadows,
shorelines, and roadsides. Each 4 to 7 foot plant produces 30 or more beautiful purple spikes that
bloom in late summer and can produce over 2.5 million seeds.
Big Cove is ringed by thousands of purple loosestrife plants whose beautiful, but unwanted magenta
flowers, create a real threat to the health and survival of that wetland shoreline. Wetlands are the
most biologically diverse productive component of our ecosystem. Numerous species of plants, birds,
mammals, reptiles, insects, fish, and amphibians rely on healthy wetland habitat for their
survival.
Once established, purple loosestrife frequently becomes the dominant vegetation by out-competing native
plants. As native communities are reduced, so, too, are wildlife species that depend on them. Declines
in ducks, geese, and other wetland birds as well as muskrats, mink, and some amphibians have all been
noted. There is also some concern that purple loosestrife may reduce spawning habitat for some fish.
Purple Loostrife |
Purple Loostrife
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Methods of Controlling Loosestrife
If dealing with a few isolated plants, cover the flowering spikes with a plastic bag, and dig the plants up, being
careful to get all the root system. All plant material should be dried and burned, or placed in a closed black
plastic bag in the sun for several days where high heat will kill the plant and seeds.
Where permitted, plants may be treated with an approved herbicide. RODEO is an effective herbicide. However, it is
non-selective and will kill most vegetation it contacts. Spot sprays directed at the early flowering stage are most
effective. Broadcast sprays are not recommended.
Loosestrife-eating beetles introduced into Big Cove in 2006
A natural enemy of purple loosestrife is the galerucella beetle, which feeds on bud, leaf, and stem
tissue. The Michigan Department of Natural Resources has successfully used these beetles for control
since 1994. Once introduced, it takes 3 to 15 years for the beetles to get purple loosestrife under
control. Galeruclla beetles eat only purple loosestrife and pose no threat to humans or pets.
Several dozen of these loosestrife eating beetles were collected by Dave and Cyndy Foley near Petoskey
in June and placed on Big Cove plants. By summer’s end some plants had been destroyed but this project
will require an ongoing program of introduction of Galerucella beetles. The beetle collection was
coordinated by the Tip of the Mitt Watershed Council. In June a group from the Lake Mitchell
Association will again collect and release beetles. |
Cyndi Foley places beetles on Big Cove
plants
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To learn more about purple loosestrife go to: www.miseagrant.org.
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