Did you know that over application of lawn fertilizer can lead to serious water quality issues in our local rivers and streams? It takes just one (1) pound of phosphorus and seven (7) pounds of nitrogen entering a waterway to produce 500 pounds of algae. As we enter the winter months it is a good time to examine your fertilizer practices. Lawns are dormant in the winter months and cannot take up the fertilizer you might apply. In fact, most established lawns do not need fertilizer at all as there is already enough nutrients in the soil to sustain plant life.
Waterkeepers Chesapeake is encouraging residents of the Chesapeake Bay watershed to take pledges to adopt water-friendly practices through our Clear Choices Clean Water campaign. Pledge takers can promise to abstain from using harmful lawn fertilizers, to clean up after their pets, to plant native plants, and to use best practices in farming and gardening in order to maintain healthy soil.
The Lawn Fertilizer Pledge asks homeowners, farmers, and golf course managers in the watershed alike to abstain from using any kind of lawn fertilizer, whether it be organic or inorganic, manure or bone meal. All fertilizers cause excess nutrients like nitrogen, phosphorus, and potassium to runoff into local waterways. These nutrients support the growth of algae, which can ultimately cause algae blooms that can produce toxins such as the cyanobacteria in freshwater. These algae blooms also contribute to eutrophication, the depletion of oxygen in a waterway, when they die. Eutrophication stresses aquatic life and in extreme cases, when there is no longer any oxygen in the area, it can create a dead zone where no aquatic life can survive. There is currently a dead zone in the Chesapeake Bay that is approximately 1 cubic mile in 2020.
The state of Maryland has a law banning the use of lawn fertilizer between November 16th and February 28th, helping to block excess nutrients from entering the waters of the Chesapeake Bay. Similar laws exist in the neighboring states of Virginia and New Jersey. In 2010, several states began to ban phosphorus in lawn fertilizer due to its impacts on water quality. Today, most fertilizer companies have stopped using phosphorus in their fertilizers.
However, if you do choose to use lawn fertilizer, you can still minimize the impact you make on your watershed by following a few easy steps. These steps include never mowing lower than 3.5 inches, leaving your lawn clippings on the lawn, avoiding phosphorus, limiting the amount of fertilizer that you use, keeping fertilizer off of impervious surfaces, using natural pest and weed control, keeping fertilizer at least 15 feet away from waterways, and making sure not to apply fertilizer before a rainfall.
Learn more about the campaign at http://mychesapeake.clearchoicescleanwater.org.