Many strive for a dark green and lush lawn which homeowners can achieve with frequent watering, fertilization applications, and herbicides. However, the steps you take to create the perfect yard can impact our lake's water quality and health. To help Lake Leelanau waterfront owners understand these impacts, the Lake Leelanau Lake Association (LLLA) hopes to offer lawn fertilization guidance and tips to help you make informed choices that will protect the health of Lake Leelanau.
Lawn Fertilizers 101
Let’s talk about fertilizers. Lawns need nitrogen (N) to thrive. Many lawn services recommend four to five nitrogen applications per year for a robust yard.
One of the reasons for the frequent application of nitrogen is that it is highly soluble in water. What does this mean? Rain and lawn irrigation wash the nitrogen out of the grass root zone and into the shallow water table surrounding the lake. Eventually, much of the nitrogen makes its way into the lake.
Just as nitrogen provides nutrients for the grass on your lawn, it also provides nutrients to the aquatic plants and algae in the lake. This can result in excessive aquatic plant and algae growth and lead to lower water oxygen levels and nuisance or harmful algal blooms.
The following guidelines serve as a good model, but a soil test is always a good starting point to determine your soil’s chemical composition before adding fertilizer.
The MSU Extension now offers a soil testing program for Michigan residents, in which you mail in your soil sample and receive information about the nutrients in your soil, personalized recommendations for fertilizers, and other important information. The mail-in home lawn and garden soil test only costs $26 and is available on the MSU Extension’s website.
If you have already done a soil test or looking for general guidelines, the following are the MSU Extension’s guidance on law fertilization based on the desired type of lawn:
- High Maintenance situations require a high-quality, uniform, dense lawn, and an irrigation system is available. A maximum of 4 lb. nitrogen (N)/1,000 ft² could be applied when distributed over four to five applications.
- The Medium Maintenance situation is for most general lawn areas where no supplemental irrigation will be applied. Still, the intention is to optimize turf grown for quality and density—a maximum of 3 lb. N/1,000 ft² could be spread over three applications.
- The Low Maintenance situation is intended for lawn areas to maintain a basic stable surface of turfgrasses, and if you live near a lake or stream, no more than 1-2 lb. N/1,000 ft² should be applied over one to two applications.
- If you choose to use commercial fertilizers, apply at most 1 lb. N/1,000 ft² at any one time, as it will burn your lawn.
Did you know that Michigan soils are naturally high in phosphorus, another essential lawn nutrient?
In 2010, the Michigan Legislature passed a law (Michigan Fertilizer Law 1994 PA 451, Part 85, Fertilizers) prohibiting the application of lawn fertilizer containing phosphorus, with certain exceptions, because of its adverse impacts on lakes and streams.
Here are the highlights from the Michigan Fertilizer Law:
- Prohibits applying phosphorus to lawns unless a soil analysis demonstrates the need or you are seeding a new lawn.
- Requires fertilizer on impervious surfaces to be cleaned immediately to prevent it from being washed into a lake or stream.
- Prohibits fertilizer application within 15 feet of surface water to prevent run-off high in nutrients.
Another interesting aspect of lawn fertilization is that you can achieve and maintain a healthy lawn with similar results to the above through organic compost supplements and lakewater irrigation.
Composting is a controlled, aerobic (oxygen-required) process that converts organic materials into a nutrient-rich soil amendment or mulch through natural decomposition. You can compost at home using food scraps from your kitchen and dry leaves and woody material from your yard.
If you need more compost than you can create, you can contact:
- Local plant nurseries for sources of clean compost
- Landscape companies to deliver and apply the compost.
Lakewater irrigation is also a more sustainable option for Lake Leelanau waterfront owners. Our lake contains many natural-occurring nutrients that can feed your lawn without fertilizer.
By common law, owners of property abutting a lake or stream may, as a property right, make reasonable use of the water as long as they use it on the lakefront property.
The Michigan Department of Environment, Great Lakes and Energy (EGLE) encourages lake water irrigation and allows lakefront owners to install and operate irrigation pumps without permits.
In summary, having a bright green lawn can take a lot of nitrogen and harmful chemicals. We recommend backing off the lush lawn concept and irrigating your yard with lake water. If the soil requires more nutrients, we recommend organic compost. And if you use a commercial fertilizer, apply it lightly and follow the Michigan fertilizer law practices.
As always, please consider reducing your lawn area by planting native plants and trees. See our previous articles on Shoreline Best Management Practices and Native Shoreline Plants for more information.