Eurasian milfoil (Myriophyllum spicatum) is an exotic plant, meaning that it is not native to Michigan.
Herbicides are applied in Wixom Lake to control Eurasian milfoil and other nuisance aquatic plants.
Harvesting is used to remove nuisance plants other than Eurasian milfoil.
Wild celery (Vallisneria americana), also known as eelgrass, is a native plant that sometimes grows to nuisance densities in Wixom Lake.
Algae are microscopic plants that can form unsightly surface scums in Wixom Lake.
Much of the aquatic vegetation in Wixom Lake consists of species that are native to Michigan. Aquatic plants provide habitat for fish and are generally viewed by biologists as being an asset to the lake. Other species are not native to Michigan and can cause problems. One such plant is Eurasian milfoil.
Eurasian milfoil is a fast-growing plant that grows to the surface and can form a dense canopy. This canopy shades out other more desirable plants and can be a hindrance to both boating and swimming. Controlling this plant is the main focus of the lake management plan.
Harvesting of milfoil is, however, not a real option since the plant spreads by fragmentation. To harvest milfoil is to spread it. Any attempt at control of milfoil must be done either chemically or biologically. There have been tests and trials with a weevil that eats milfoil. While some limited success has been reported using weevils, they do not seem to provide widespread control in large areas. The jury is still out on their scope of application.
Chemical treatment for milfoil is then where most of the effort and cost will be concentrated. Several different chemicals are available for use against milfoil. Each has advantages and disadvantages.
2,4-D is a systemic chemical, meaning it kills the entire plant, roots and all. 2,4-D has historically been one of the most successful chemicals used against milfoil. One of the drawbacks to it is a restriction around drinking water wells, particularly shallow wells.
Triclopyr (brand name Renovate) is a newer chemical approved for aquatic use. It is also a systemic chemical but it has a somewhat lengthy restriction to not use the water for irrigation. It has been used in Wixom Lake since 2003 and performed quite well. The irrigation restriction is typically lifted after a period of approximately three weeks. A pellet version of the product has been used since 2007. The pellet version is particularly effective in the open water areas while the liquid formulation is more suited for the canals.
Diquat dibromide is another available chemical which does not have a well setback restriction, but it is a contact herbicide, rather than a systemic one. This means that it kills only the portions of the plant with which it comes into contact with. It does not translocate and kill the root of the milfoil.
A new contact herbicide, flumioxazin (brand name Clipper), has shown to be effective in canal areas and may be used in shallow weed-infested areas.
Fluridone (brand name Sonar) has also been used successfully against milfoil, most notably at Houghton Lake. It is a systemic herbicide which requires a long contact time of 45 to 60 days. Because of the constant flow of water through Wixom Lake, a pelletized, slow-release version of Sonar was tested in 2004. Unfortunately, high flows after heavy rains in late May compromised the project. It is unclear if or when this product may be used again.
The Wixom Lake herbicide treatment notice lists the herbicides that may be applied to Wixom Lake this year. At the time of treatment, signs will be posted along the shoreline in treatment areas. The signs will list the herbicides that were applied in that area, and the associated use restrictions.
One part of the management plan is for the cutting and removal, or harvesting, of plants. This procedure will be implemented in areas of native weeds which are so dense as to cause problems for boating. This generally means that a lane will be cut so that people can get their boats from their docks out to open water. There are several drawbacks to harvesting. The harvester is not maneuverable enough to cut between docks; it needs 2 to 3 feet of water and the many stumps in the lake can be a huge concern. It is also a very temporary solution to the plant control program.
Other Nuisance Aquatic Plants
Curly-leaf pondweed is another exotic weed which can reach nuisance densities. It responds well to diquat dibromide treatments.
Wild celery (also known as Eelgrass) is a native weed which can become a nuisance, particularly near shore. It grows later in the season and can become a problem after mid July. It can be treated with a copper-based product called Nautique. The treatment knocks down the plants but typically does not kill them.
Algae is a non-rooted plant which can develop in hot, dry weather. It often forms an unpleasant scum on the water surface. A treatment with copper sulfate temporarily controls this problem. Potentially longer-lasting alternatives to copper are being evaluated for use on Wixom Lake.
The Wixom Lake Improvement Board operates the aquatic plant control program under rules and objectives, described here.
Areas of Wixom Lake to be treated or harvested are determined by biologists from Progressive AE who conduct surveys of the lake. If you feel that your area of the lake has not been adequately treated or harvested, you may fill out a Wixom Lake complaint form.
An overall summary of the Wixom Lake aquatic plant control program can be found here.
Still have questions? Click here for our frequently asked questions page.
Gladwin and Midland Counties, Michigan