The “Look for the Zero campaign,” launched by the state’s Department of Environmental Conservation last year, encourages homeowners to go phosphorus-free when using lawn fertilizer. More than 100 water bodies in New York State cannot be used or enjoyed due to phosphorus overuse.

Fertilizer labels have three numbers. The number in the middle is the percentage of phosphorus in the product, such as: 22-0-15.

Phosphorus has been the focus of recent Harmful Algal Bloom summits held in four locations throughout New York. The summits brought together community leaders, national and local experts, and state agency officials to develop strategies to address the harmful blooms in New York.

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 that the lawn does not have enough phosphorus. Generally, only newly established lawns or those with poor soil need phosphorus.

Phosphorus applied to already existing lawns should not be used and can cause water pollution. 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 recreation. Municipalities lose revenue when they must close beaches or boating areas, according to a release from 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. The DEC is encouraging consumers to review bag labels for phosphorus content when shopping for fertilizer.

Homeowners are encouraged to practice more sustainable lawn care and to choose native plants and grasses, which adapt to local climate and soil conditions. These plant species provide nectar, pollen, and seeds that serve as food for native butterflies, insects, birds, and other animals.

Organic lawn care can easily be used on any lawn, the release says, noting safe and effective alternatives exist for most chemical pesticides and fertilizers. Organic lawn-care treatments promote deep root systems, natural photosynthesis, and longer grass growth. The DEC’s Sustainable Landscaping web page tells more: www.dec.ny.gov/public/44290.html.

Additional recommendations for sustainable lawn care include spreading a quarter of an inch of compost on the lawn to improve moisture retention and soil texture and to add beneficial microorganisms and nutrients. Another suggestion is to allow grass to grow three inches tall and then cut no more than one inch off the top.

This is the “one-third rule” that helps develop a deeper root system, which is a natural defense against weeds, disease and drought. The DEC’s Lawn Care web page has more information at www.dec.ny.gov/chemical/8816.html.

The DEC also encourages homeowners to leave lawn clippings after mowing to improve the health of a lawn. Grass clippings are 80 percent water and contain 2- to 4-percent nitrogen, phosphorus, potassium, and other nutrients. Leaving clippings also saves homeowners time after mowing and reduces the amount of garbage thrown out. Grass clippings can account for as much as 10 percent of garbage.

New York’s nutrient runoff law does not affect agricultural fertilizer or fertilizer for gardens.