Keeping Your Grass Legal

A new state law requires everyone—homeowners, lawn services, commercial property owners—to get a soil test before applying fertilizer that contains phosphorous to their lawn.


If a law passes on Beacon Hill and no one notices, did it really pass?

Last year, the Legislature passed a law regulating the sale and application of lawn fertilizers containing phosphorous, a powerful water pollutant that spurs unsightly and often toxic algae blooms in freshwater rivers and streams.

In June, the regulations implementing the new law took effect, with nary a word of coverage in the media.

The new regulations, administered by the Mass Department of Agricultural Resources, go by the catchy title: “Plant Nutrient Application Requirements for Agricultural Land and Land Not Used for Agricultural Purposes” or 330 CMR 31.00. With a name like that, maybe all the TV crews who were going to cover this issue dozed off before they could finish reading the title and missed their deadline.

New Requirements for Every Lawn Including Yours

The law requires everyone—homeowners, lawn services, commercial property owners—to get a soil test before applying fertilizer that contains phosphorous to their lawn.

lawn fertilizer label

Phosphorous is the “P” in the infamous “N-P-K” rating that appears on every bag of fertilizer.

The law also prohibits applying more P to your lawn than is called for in the soil test results, which for most lawns will mean not applying any P at all. P is generally stable over time in an established lawn, getting recycled back and forth between the grass and the soil, but not getting “used up” from year to year. So unless you are starting out with a deficit, there’s really no reason to add more every year, though many people do.

The law also directs retailers who sell lawn fertilizers to keep products that contain P separate from other fertilizers and to label them as potentially hazardous to your local river or stream. See the bottom of this page for a more detailed summary of the law’s provisions, or you can read the regs on the state website.


Talk to Your Landscaper

Think you’re safe because you rely on a professional lawn service to to manage your lawn? Think again.

The law provides for enforcement against not only the person who applies unneeded P, but anyone who “authorize[es] any person, by way of service contract or other arrangement, to apply” P.

In short, you are liable for violations of the new phosphorous law on your property, even if it is your landscaper who is deciding how much P to apply to your lawn. So ask your landscaper a few simple questions:

  • Are you applying fertilizer containing phosphorous to my lawn?
  • Have you completed the required soil test for P and are you following the soil test recommendations?
  • Are you in compliance with the record keeping and other provisions of the new law?
  • Are you mulching my grass clippings and blowing stray clippings back onto the lawn?
  • How many pound of N are you applying to my lawn a year, and what’s the most you apply at any one time?

A Case of Overreach or a Smart Protection for Taxpayers?

Is this an example of legislative overreach or an extremely sensible way of protecting the environment and saving millions for municipalities? The push for adopting the law came primarily from municipalities, who have for some time been anticipating much more stringent regulations from EPA requiring them to reduce the amount of P they discharge to rivers and streams through their storm drain outfalls that collect runoff from streets, parking lots and driveways.

Storm Drain 1

Grass clippings and leaves contain large amounts of N and P, which is why its important to blow or sweep clippings off the pavement and back onto the lawn when you mow.

The concept behind the law is to prevent the pollution before it starts, at the homeowner and landscaper level, rather than making municipalities spend millions perhaps—$180 million by one estimate—trying to cleanup excess fertilizer that runs off lawns into storm drains after the fact. Aside from saving millions for towns, it should save money for homeowners as well, since they won’t be buying and applying phosphorous fertilizers that their lawns don’t need.

But there’s a rub. If the law passes, and EPA reduces the pollution reduction requirement that it imposes on the towns, but no one publicizes or enforces the law, then the loser will be the environment.

That’s why we are advocating for all Neponset Watershed towns to undertake meaningful public outreach programs around the new law, including mailings, press releases, and face to face contact with landscapers and fertilizer retailers. We are also calling on the Baker Administration to provide the Department of Agricultural Resources with a budget to publicize and enforce the law on a statewide level.

What About N?

The P in “N-P-K” is not the only problem for our waterways. Where P stimulates explosive growth of toxic algae in freshwater systems, Nitrogen or N, does the same thing in saltwater estuaries and bays, but isn’t covered by the new law. When someone applies too much fertilizer containing N in Foxborough, it gets washed into storm drains and transported 29 miles downstream to the Neponset Estuary and Boston Harbor where it stimulates algae that cloud the water making it unsuitable for fish, shellfish and swimming, and in severe cases causes salt water dead zones with no oxygen, where nothing can live.

Swimming at Tenean Beach in the Neponset Estuary

Swimming at Tenean Beach in the Neponset Estuary

N may have been omitted from the law in part because EPA has not been threatening to regulate it. However, N also requires a different approach, since it doesn’t remain at steady levels in the soil that can be measured with a soil test like P.  With N, it is a matter of applying a little bit, but not too much, every year.

While it is not regulated, there is some very good, recent guidance that we urge everyone to follow. Thankfully it comes with an equally horrible name: the Northeast Voluntary Turf Fertilizer Initiative prepared by the New England Interstate Water Pollution Control Commission.

The key tidbit of information from this cleverly named document is this: in nitrogen sensitive areas (which in our opinion includes the entire Neponset Watershed) you should apply no more than 2.0 pounds of total nitrogen per 1,000 square feet of lawn per year, and never more than 0.7 pounds per 1,000 square feet at any one time.

Taking things one step further, the turf gurus at the UMass Extension Service recommend that you should always mulch grass clippings and leave them behind to decompose rather than bagging them, and when you do that, you should reduce your nitrogen application by 1.0 pound per 1,000 square feet per year.

Whether you mulch or not, these recommended application rates for N—1 pound per 1,000 square feet per year if you mulch your clippings, and 2 pounds if you bag—are generally lower that those put forward by firms marketing the perfect lawn irrespective of the environmental cost.

You can find the full report of the Voluntary Turf Fertilizer Initiative on the NEIWPPC website, along with the easier to digest short version of the recommendations which weighs in at three pages.

Reconsider Perfection

Whether you hire a lawn service or maintain your own lawn, we also urge you to reconsider the goal of a perfect lawn. In many realms of life, the pursuit of a “perfect” appearance ends up being harmful, and that is certainly the case when it comes the environmental consequences of the quantities of water, fertilizer, lime, herbicide, pesticide and petroleum required to achieve the “perfect” lawn. Its surprising how much healthier and less expensive it is to aim for good, nice, or “just fine,” rather than perfect.

Summary of MA Turf Fertilizer Phosphorous Regulations

This is only a summary, for complete rules, view the complete regs (330 CMR 31)

  • No application of phosphorous containing fertilizer unless you have had a soil test performed on your yard in the last three years that says you need more, or you are in the first year of installing a new lawn or renovating an existing lawn (overseeding an existing lawn doesn’t count as “renovation”).
  • Soil test must be done following UMass guidelines on lab and sampling procedures (we recommend just using the UMass Soil Testing Lab which is cheap and easy)
  • No fertilizer application (even fertilizer without P)
    • In the winter (Dec-March) or on frozen ground
    • When heavy rain is forecast in 24 hours
    • Within 20 feet of wetlands or waterways (10 feet with a drop spreader)
    • Within a Zone I wellhead protection area of 100 fee of surface drinking water supplies
    • In excess of the UMass guidelines
    • Onto a paved or impervious surface (we recommend staying 10 feet back from paved surfaces since these usually drain right to a waterway or wetland)
  • When calculating how much P and N to apply, you must also account for the P and N included in any organic fertilizer, compost or other treatments that year.
  • Professionals who apply fertilizers must keep detailed records of what and how much was applied and when for each customer and these records are subject to inspection.
  • Fertilizer retailers must display fertilizers containing P in a separate area and must mark it with an 11 x 17 or larger sign notifying people of the soil testing requirements (see regs for specified language).

Ian Cooke, Executive Director, Aug. 2015

2 responses to “Keeping Your Grass Legal”

  1. Jackie says:

    Thanks for this important update. I’ve begun converting my lawn to clover and wonder if that is an alternative that you could address in future issues? It is doing wonders for the “lawn”, is drought resistant, soft and is helping with an erosion struggle I’ve had for years. Plus the need for mowing is almost nonexistent and I have more bugs, bees, birds and butterflies in the yard than I’ve ever experienced. Great way to naturally go green and no need for fertilizer that I can determine.

    • Ian Cooke says:

      Thanks Jackie! You are correct planting clover (you can buy it as seed) is a great way to add nitrogen to your lawn and reduce or eliminate the need for synthetic fertilizer. Clover is one of a number of plants that can “fix” its own nitrogen, otherwise known as pulling the nitrogen it needs out of the air. Our atmosphere is composed largely of nitrogen gas, but few plants can make use of this abundant supply. In so doing, clover can not only meet its own nitrogen needs, but can add nitrogen to the soil for the benefit of other plants too. One of the biggest problems with lawn weed control herbicides, is that they kill off the clover, which then forces you to add more synthetic nitrogen fertilizer to compensate. Thanks for pointing out this smart green practice!

      Ian Cooke

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