LINAP’s Springtime Tips For Lawn Fertilization To Improve Water Quality
Spring’s arrival means many Long Island homeowners will strive for a lush, green lawn. Before applying lawn fertilizer,
the Long Island Regional Planning Council (LIRPC) and Long Island Nitrogen Action Plan (LINAP) urge residents to
follow LINAP’s recommendations for proper lawn fertilization and irrigation.
“Our foremost recommendation is not using any fertilizer,” said Kyle Rabin, LIRPC program manager. “If homeowners
like how their lawn looks, fertilizer is unnecessary.”
Fertilizer is the second-leading source of nitrogen contamination of Long Island waters; residential wastewater
is the primary source. The nitrogen in fertilizer finds its way into waterbodies, stimulating the excessive growth of aquatic
plants and algae that consume dissolved oxygen and block sunlight. Overwatering lawns compounds the problem because
it increases the amount of runoff.
“People think more is better—more fertilizer and more water will create a better result. That notion is incorrect and has serious
environmental impacts. Knowing when to fertilize and how to do it properly can protect water quality and result in a healthier
lawn,” Rabin said.
Those choosing to apply fertilizer are encouraged to follow these recommendations from LIRPC and LINAP:
* Fertilize lawns and non-agricultural turf between April 2 and Oct. 31. Do not fertilize between Nov. 1 and April 1.
This recommendation is, in fact, law in Suffolk County. In Nassau County, the prohibited period is Nov. 15 to April 1.
* Use a fertilizer containing at least 50 percent slow-release nitrogen. This type of fertilizer releases the nitrogen slowly
over time so the grass can take up the nitrogen as needed. Fertilizer retailers can direct shoppers to slow-release nitrogen
products. Some retailers have helpful online resources about products with slow-release nitrogen.
* Only apply lawn fertilizer to grass. Do not apply fertilizer on any impermeable surfaces, such as driveways, sidewalks,
frozen ground, parking lots and storm drains, or where there is standing water on turf.
* Keep grass clippings on your lawn. The clippings are a great source of natural, slow-release nitrogen. By leaving the grass
clippings on the lawn, you can reduce the amount of fertilizer you apply by 25 to 50 percent, which will protect the water
and save you money.
* If irrigating a lawn, only apply up to 1.5 inches of water per week beyond rainfall and do not water between 10 a.m. and
4 p.m. or during rainfall. Be careful when applying fertilizer close to the water. Do not apply fertilizer within 20 feet of any
surface water, except where there is a continuous 10-foot wide natural vegetative buffer.
The turf-grass fertilizer recommendations can be found here: https://www.dec.ny.gov/docs/water_pdf/linapfertilizer.pdf.
NYSDEC and LIRPC led a workgroup to develop the recommendations. The workgroup included environmental groups,
fertilizer manufacturers, landscaping companies, nursery operators, garden supply retailers, golf course superintendents,
and representatives from farming and government. The recommendations are also based on scientific and experiential
information from the Cornell Cooperative Extensions of Suffolk County and Nassau County, Suffolk County Department
of Economic Development and Planning, Cornell University, and the University of Connecticut.
LINAP is led by the New York State Department of Environmental Conservation (NYSDEC), LIRPC, and Suffolk and Nassau
counties, and includes local governments, area scientists, engineers, environmental and non-governmental organizations, and
several supporting professionals.