It’s spring and lawn care is on the minds of many Long Islanders. Fertilizer is often thought of as a key ingredient to a healthy, vibrant lawn.
But fertilizer use, especially improper application, can be harmful to the environment. The nitrogen in fertilizer pollutes our waterways, negatively impacts aquatic life and interferes with fishing, swimming and boating. In fact, fertilizer is the second leading source of nitrogen contamination of Long Island waters; residential wastewater is the primary source.
In the March issue of the Long Island Nitrogen Action Plan (LINAP) newsletter, they reviewed several ways to care for your lawn while protecting coastal waters, as well as, our drinking water supply. Most important, fertilizer should not be applied before April. Grass simply cannot efficiently absorb fertilizer at this time. Furthermore, it is illegal to fertilizer your lawn in Nassau and Suffolk counties before April 1.
To be clear, lawns are not a natural landscape feature and usually require high maintenance. If having a lawn is your preferred landscape option, then following the suggestions below will help decrease the likelihood of overapplying fertilizer and, therefore, reduce the amount of excess nitrogen that enters groundwater and surface water.
1. Don’t start fertilizing. If you’re not currently using fertilizer and you are happy with how your lawn looks, then maybe you don’t need to fertilize at all! Many lawns do not need any added fertilizer to spark joy in the homeowner.
2. Keep those grass clippings on your lawn. Mulching mowers finely chop grass into small pieces which get deposited into the lawn and decompose quickly. It is like adding a little bit of fertilizer every time you mow, and allows you to lessen, or eliminate, chemical fertilizer application. As a general rule, no more than a third of the grass blade should be removed during a single mowing. And it’s also good practice to keep the height at least three inches high, which encourages deeper, healthier roots.
3. Apply less fertilizer to your lawn. If you decide to use fertilizer, especially on a well-established lawn, then apply one-third to one-half the amount recommended on the fertilizer bag. If you are satisfied, then you applied the right amount. Nice work!
4. Calibration is key. If you choose to fertilize, you’ll need to calibrate your spreader in order to deliver fertilizers at the correct application rates. Equipment used to spread fertilizer should be calibrated for a single application rate of a maximum of 0.6 pounds of total nitrogen per 1,000 square feet at least once annually or each time fertilizer products are changed. Calibration directions are available on the Cornell Cooperative Extension of Suffolk County website.
5. Timing is everything. If you are going to fertilize, then apply it at the right time – close to Memorial Day and/or Labor Day. Fertilizer shouldn’t be applied before April and after mid-October. Nor should it be applied during the hottest summer months when grass is dormant. Grass simply cannot efficiently absorb fertilizer at this time so don’t bother trying – you’ll just waste fertilizer and money. On Long Island, if you fertilize once a year, it makes the most sense to do so around Labor Day.
6. Eliminate or shrink your lawn. Consider reducing the lawn area requiring fertilizer. One of the most effective ways Long Islanders can do their part to protect local water resources, is to replace their lawn or a portion of it with less water-intensive landscaping, also known as “xeriscaping.” Homeowners and businesses in the western U.S. now embrace xeriscaping and Long Islanders can make the same adjustment. Xeriscaping, which makes use of native plant species, requires little to no fertilizer and can help to absorb and filter rainwater. Also, xeriscaping is aesthetically pleasing and can increase property value.
These valuable and effective suggestions are part of a set of recommendations from the Long Island Nitrogen Action Plan. The recommendations, linked to below, include best practices designed to balance residents’ interest in having a green and healthy lawn with the immediate need to reduce nitrogen loads to surface waters and groundwater.
The LINAP recommendations will help curb the pervasive over-application and misapplication of nitrogen-laden fertilizers, which enter our harbors, bays and other large surface water bodies, as well as leach into our groundwater. Issued in 2019, the recommendations were informed by a workgroup that included environmental groups, fertilizer manufacturers, landscaping companies, nursery operators, garden supply retailers, golf course superintendents and representatives from farming and government.
For more information, please visit the following resources:
NYS DEC Lawn Fertilizer webpage
NYS DEC LINAP’s Turf Grass Fertilizer Recommendations
NYS DEC “Leave it on the Lawn” webpage