Has Purple Loosestrife Invaded Your Lake or Stream?
by Carol Kuesel (slpoatc@gmail.com) of Spider Lake, Traverse City
Purple Loosestrife - Lythrum salicaria (A.K.A. Purple lythrum, Rainbow weed, and Spiked loosestrife) is an attractive herbaceous, perennial with squarish stems that grow 1.5 to 6’ tall which are topped with spikes of many, tiny generally purple (sometimes white and pink) flowers each with 5 to 7 petals. The flower spikes bloom from July to October. However, Purple Loosestrife spreads so vigorously in moist soil conditions via roots and seeds (millions per plant) that it crowds out native wetland plants. Thus, it is considered an invasive plant and is restricted under Michigan law.
The Northwest Michigan Invasive Species Network includes Purple Loosestrife in its “Top 12” list of invasive plants (https://www.habitatmatters.org/purple-loosestrife.html).
The Midwest Invasive Species Information Network also includes Purple Loosestrife in its list (https://www.misin.msu.edu/facts/detail/?project=misin&id=32&cname=Purple+loosestrife).
Spreading Invasives
Purple Loosestrife has spread to a multitude of properties around Spider Lake (an “Up North” inland lake) in clusters from one or two plants to larger groupings of hundreds of plants that have established “new” monoculture, unusable land due to sedimentation around its roots and branches. Notably, two of the largest groupings are at the DNR public boat launch.
Establishing an Action Plan
Members of the Spider Lake H2O Quality Committee are beginning to form a plan to inform our fellow riparians about Purple Loosestrife and to begin to remove it. We hope to engage experts to help us develop a plan that will not only help us, but be available to others throughout Michigan. In that endeavor, we are seeking to learn how many other Michigan lakes and streams have Purple Loosestrife. Additionally, we are also looking for suggestions on how others are addressing control/eradication of it.
Your Input is Needed!
If your lake/stream has Purple Loosestrife, please complete the following survey by Friday, November 20. If you are interested in receiving a copy of the results, please email MLSA Executive Director, Melissa DeSimone: melissa.desimone@mymlsa.org
Does your association need assistance?
Michigan Lakes and Streams Association wants to help member associations like Spider Lake and you!
Please feel free to reach out to MLSA for help with your lake or stream related issue. We want to help you, send us an email: info@mymlsa.org.
Check out our website: mymlsa.org for resources on aquatic invasive species and other water protection topics.
Join MLSA and Make a Donation to help us preserve and protect Michigan's inland lakes and streams.