The New York State Department of Environmental Conservation’s annual “Look for the Zero” public awareness campaign has returned to encourage homeowners to go phosphorus-free when using lawn fertilizer.
More than 100 water bodies in New York State cannot be used or enjoyed because of phosphorus overuse, according to the DEC, which wants consumers to review fertilizer bag labels for phosphorus content before buying.
Fertilizer bags have an N-P-K number that shows the percentage of nitrogen, phosphorus and potassium that the product contains. So, for example, a bag labeled 22-0-15 is a high-nitrogen fertilizer with no phosphorus at all. Nitrogen causes grass blades to grow and green up. Phosphorus is necessary for root growth, but it is generally already present in soil so applying more is unnecessary for the grass and harmful for waterbodies.
“Despite some recent winter-like weather, spring is here and property owners are outside working to make sure their lawns look good,” DEC Commissioner Basil Seggos said. “But there’s more to it than just green grass. We want New Yorkers to look for the zero on the fertilizer bag before bringing it home. Excess phosphorus is a threat to many New York waterbodies, triggering algae blooms and sometimes rendering waters un-swimmable and un-fishable. If New Yorkers implement sustainable lawn care methods, we can help dramatically reduce phosphorus and pesticide use on lawns, which will protect water quality and public health while maintaining healthy backyards.”
New York’s nutrient runoff law prohibits the use of phosphorus lawn fertilizers unless a new lawn is being established or a soil test shows the lawn does not have enough phosphorus. Generally, only newly established lawns or those with poor soil need phosphorus. Regardless of the location, excess phosphorus from lawns can wash off and pollute lakes and streams, harming fish, pets, or people that use these waters for recreating and a source of revenue for towns that must close beaches or boating areas, according to the DEC. New York State law requires retailers to post signs notifying customers of the terms of the law and to display phosphorus fertilizer separately from phosphorus-free fertilizer.
To further reduce fertilizer use, the DEC is also encouraging homeowners to choose native plants and grasses, which are adapted to the local climate and soil conditions. These plant species provide nectar, pollen and seeds that serve as food for native butterflies, insects, birds and other wildlife, the DEC notes.
The DEC also recommends spreading a quarter-inch of compost on the lawn to improve moisture retention and soil texture while adding beneficial microorganisms and nutrients.
To help grass develop a deeper root system — a natural defense against weeds, disease and drought — the DEC says to follow the one-third rule: Allow grass to grow 3 inches tall before cutting no more than 1 inch off the top.
One of the DEC’s most vital sustainable lawn care tips is to leave lawn clippings after mowing with a mulching mower. The clippings are mostly water and they also provide the lawn with appropriate amounts of nitrogen, phosphorus and potassium, among other nutrients.
For more information on the state’s nutrient runoff law, visit dec.ny.gov/chemical/67239.html.