Lawn – Neponset Stormwater Partnership

You can have a great lawn, save money, and protect local waterways!

There are many options to consider when caring for a lawn. For example, unless you’ve had your soil tested, you may not know exactly how much fertilizer to use on your lawn. Without that vital information, you could be overusing fertilizer – and wasting your money.

There is an environmental impact to fertilizer use as well. Improperly applied fertilizer can easily wash into local waterways through storm drain systems and cause problems in local streams and ponds. Fertilizers cause algae to grow, which can deplete oxygen, hurt aquatic wildlife, and make boating, fishing, and swimming unpleasant.

Try these alternatives to fertilizer:

Set your mower to a “mulch” setting. This will chop up grass clippings and leave them on your lawn. As they decompose, they will release nutrients back into the soil.
Encourage the growth of clover and other legumes in your lawn. Legumes take nitrogen from the air, convert it into a form that is usable by your lawn, and store it in the soil.
Mow your grass at a longer length, but more often. This will stress the lawn less, encourage root growth, and (BONUS!) make your lawn more drought-tolerant.

If you must use fertilizer, plan responsibly.

Do not use fertilizer with phosphorus unless you get a soil test. Phosphorus pollution is such a problem in Massachusetts that it is illegal to apply phosphorus-containing fertilizer without a soil test stating it is necessary.
Test your soil at least once every 3 years to learn what your lawn needs to be healthy. UMass Amherst offers a convenient soil testing option.
Make sure the pH of your lawn is in the acceptable range (this stat will be shown on your soil test). If the pH is too high or low, the plants will not be able to absorb the nutrients, regardless of how much you apply.
Choose organic or slow-release fertilizers whenever possible. This allows for a slow, sustained release of nutrients after application rather than a heavy, all-at-once dose.
Test homemade compost prior to application so you know the actual nutrient content of the material. Knowing the content will allow you to calculate an acceptable application rate. Unfortunately, UMass no longer tests compost, but they direct to their colleagues at Penn State and the University of Maine for these services.

Apply it responsibly, too.

Use the appropriate amount of fertilizer (only when recommended by a soil test) and spread it evenly across your lawn.
Do not apply fertilizer to the bare ground (unless you are reseeding).
Sweep up any fertilizer spills from impervious surfaces (driveways, sidewalks, etc.).
Do not apply fertilizer near any bodies of water.
- It is against state law to apply fertilizer within 100′ of a water body used for drinking water and within 20′ of any water body when using a broadcast spreader.
After application, lightly “water in” the fertilizer by gently applying 1/4″-1/3″ of water to the lawn. This will dissolve the fertilizer without causing it to run off.
Maximize the effectiveness of your fertilizer and apply it in several smaller application events spread out over the growing season.
- Never apply more than 0.9 pounds of nitrogen per 1000 square feet during any one application event.
- If your lawn has exposed bedrock, nearby wells, nearby waterways, steep topography, or sandy soils, the recommended maximum is 0.7 pounds of nitrogen per 1000 square feet.
And never:
- apply fertilizer when a major rainstorm is expected within 48 hours,
- to frozen or saturated soil,
- or when the grass is dormant. Cool-season grasses that are typically used for lawns are usually dormant during the hot summer months and the cold winter months.

Dispose of yard waste properly.

As leaves and grass clippings decay, they release nutrients that can cause harm to our waterways. If the decay happens in water, such as a slow-flowing stream, it also uses up oxygen in the water and suffocates organisms that need it.

To prevent nutrient pollution from yard waste:

Sweep up any grass clippings or leaves that end up on impervious surfaces (driveways, sidewalks, etc.) Otherwise, the rain will wash them into the storm drain.
Collect and dispose of grass clippings and leaves through a town-organized program or by composting them.
Or, as an even better option, mulch your yard waste and leave it on your lawn. As the material decays it will release nutrients and green up your lawn for free!

To learn more, visit the Yard Waste page.