Are you an Aquatic Gardener?
As you boat along the shore of Lake Mitchell, you'll see lush green lawns and gardens of beautiful flowers - evidence of the care given by lakeshore property owners. But could these residents also unknowingly be aquatic gardeners helping to grow masses of weed beneath the surface of Lake Mitchell? Yes, that might certainly be true.
The fertilizer that encourages plants to grow on land, leech into a lake boosting aquatic plant growth. Leaves or lawn clippings raked or dumped into the water fall to the bottom and decompose providing a rich underwater mulch for plants to take root. Just noting that the lake bottom adjacent to your property is sandy and free of weeds, doesn't mean there isn't a problem. Fertilizer and yard waste will drift along before settling to the bottom, often near the first drop off or where there is soft bottom creating ideal habitat for aquatic plant growth.
Here are some ideas that will help insure you're not inadvertently becoming an aquatic gardener.
1. Use Phosphorus-free fertilizers and fertilizers sparingly -Rain, lawn sprinkling, and snow melt all will wash fertilizers and sediments from yards into the lake unless there is a substantial greenbelt along the shoreline. The soil in the Lake Mitchell watershed generally has more than adequate amounts of phosphorus and nitrogen to grow lawns. You may purchase a soil sample kit at the Michigan State Extension in the Wexford County Lake Street Building in Cadillac. They will test your soil to determine what, if any, fertilizers are needed. If you must use fertilizers, select bags that are phosphorus-free and with slow release nitrogen. If the label on the package has a zero in the middle such as 12-0-20 then you know it contains no phosphorus.
We must also monitor the use of Nitrogen, which is why we encourage decreased use of fertilizers in general. Nitrogen adds to weed growth and algal blooms.
The Michigan legislature has passed a law banning the use of phosphorus fertilizers that went into effect January 1, 2012. The degradation of lakes caused by phosphorus has attained national attention with several states regulating the use of fertilizers containing phosphorus. Cherry Grove and Selma Townships both have passed resolutions recommending that fertilizers on lakeshore properties be phosphorus-free. The City of Cadillac now uses only phosphorus-free chemicals on its lakefront property.
2. Create a shoreline greenbelt - A greenbelt is a band of natural vegetation,such as wildflowers, grasses, perennials, and trees growing along a lake shoreline. These buffer strips stabilize shoreline to help prevent erosion and filter pollutants and sediments. Greenbelts slow surface runoff before it enters the water, allowing sediments, excess nutrients, and other pollutants to settle out. Uncontrolled sedimentation will alter the habitat of crayfish, mayfly larvae, and fish as well as increase phosphorous loads in the lake. Leaving a strip of natural vegetation between your lawn and the water’s edge is one of the best things you can do to maintain our lake’s water quality. A bushy greenbelt along your shoreline is the best way to discourage Canada geese from invading your property.
3. Do not feed the waterfowl - It will only encourage them to reside on your lawn and leave their nutrient rich weed-growing defecation there and in the water.
4. Eliminate loosestrife or phragmites - While these plants may be attractive, they are invasive and harm native wetland vegetation. These plants should be uprooted and removed. The seeds will travel on the wind and water to new locations.
Photos of these plants are on our website.
5. Keep leaves or yard waste out of the lake - Don't rake leaves or yard waste into the lake. Leaves or grass once they decompose will provide fertile areas to grow aquatic plants. Burning yard waste near the lakeshore is not a good solution either. Ashes contain phosphorous and nutrients that can easily make their way into the lake resulting in excess weed and algae growth.