You can have a great lawn, save money AND protect local waterways!
Many people follow the same lawn care routine without really understanding what their lawn needs to be healthy. For example, your soil may already have plenty of nutrients in it for making the grass green and doesn't require additional fertilizer. Unless you or your landscaper is testing the soil, you really don't know what your lawn needs, and you could be using chemicals unnecessarily - and wasting your money.
Fertilizer that has been improperly applied to our lawn can easily be washed into storm drains by rain. Storm drains empty into the nearest waterway without any filtration or treatment. If fertilizer gets into a storm drain, it is essentially the same as it being dumped directly into the water. This can cause a lot of problems in our streams and ponds. Fertilizers cause algae to grow, which can deplete oxygen and hurt aquatic wildlife - and make boating, fishing and swimming unpleasant.
What Can I Do?
Review the tips below and make sure to follow them when performing your yard maintenance. If you hire a company for this service, have a conversation with them to make sure they are performing the work responsibly.
Don't fertilize - if you don't apply fertilizer to your lawn, there is no chance it will get into the surface waters!
Try some of the following management practices to eliminate (or at least greatly reduce) your need for 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 stores 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 still choose to use fertilizer, be sure to use it responsibly.
Following these tips will help to prevent the addition of excess nutrients to our waterways AND will also save you money by preventing your expensive fertilize from running off your lawn.
Tips for Planning Your Application
- Avoid using fertilizer with any phosphorus. In Massachusetts, phosphorus pollution is such a problem that it is actually illegal to apply phosphorus-containing fertilizer without a soil test stating it is necessary.
- Make sure to test your soil at least once every 3 years. A soil test will tell you exactly what your lawn needs to be healthy without over fertilizing. 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 will allow for a slow, sustained release of nutrients after application rather than a heavy, all-at-once dose.
- If using a "home made" fertilizer such as compost, have the compost tested 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.
Tips for Applying Fertilizer
- Apply the correct amount of fertilizer evenly to your lawn.
- Avoid applying fertilizer to bare ground (unless you are reseeding).
- If you spill any fertilizer, or if your spreader accidentally throws it onto impervious surfaces (driveways, sidewalks, etc.), be sure to sweep it up.
- Never apply fertilizer when a major rain storm is expected within 48 hours.
- Never apply fertilizer to frozen or saturated soil.
- Never apply fertilizer 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.
- Be mindful of any nearby water bodies while applying fertilizer. 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.
- Never apply more fertilizer than is recommended by your soil test.
- To maximize the effectiveness of your fertilizer, 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.
Fertilizer is not the only source of excess nutrients.
Regardless of whether you fertilize or not, your yard waste can still contribute harmful nutrients to our waterways. As they decay, these organic materials release nutrients. If the decay happens in water, such as a slowly flowing stream, it also uses up oxygen in the water, suffocating any other organisms that need it.
Follow these tips to prevent nutrient pollution from yard wastes:
- Always 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.
- Always properly manage your grass clippings and leaves by either collecting them and disposing of them through a town-organized program or composting them.
- Better yet, mulch these materials and leave them on your lawn. If they're going to decay and release nutrients anyway, it might as well be on your lawn and green it up for free!