How to Fertilize Your Lawn Without Hurting our Waterways

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It's estimated that over half of the pollution in our nation's waterways comes from stormwater runoff.

Water pollution may seem like a problem caused by industrial plants, but, as an individual, you make a difference. Anything from your property that gets into stormwater — the water from rain, snow and sleet — flows into gutters and storm drains, and then directly into rivers, lakes and streams.

“It is estimated that more than one-half of the pollution in our nation's waterways comes from stormwater runoff,” the Stormwater Coalition says.

A treatment facility for stormwater would be extremely expensive, especially considering it would sit unused most of the time, so pollution in stormwater is not treated and directly affects fish, habitats and even your ability to boat, swim and play in local creeks and lakes.

One of the major offenders from residents is fertilizer. When it gets into stormwater, algae grows (just like fertilizer helps plants grow in your yard) and uses up oxygen in the water, hurting or even killing fish and other aquatic species. The simple solution is to keep fertilizer out of stormwater. Here are six ways you can help:

Don’t fertilize before a storm

It’s an old wives tale that its best to fertilize your lawn before a rain storm. Fertilizer needs time to sink into your grass and soil so if it rains shortly after you fertilize, instead of feeding your grass, you end up polluting the stormwater; wastes your time and money. The takeaway? Check the weather and, if rain is coming, delay fertilizing.

Fertilize your lawn, not the sidewalk

Fertilizer that doesn’t stay on the lawn makes its way into storm drains. Once you’re done fertilizing, sweep any excess onto your lawn. Additionally, the Environmental Protection Agency says to leave a buffer between any waterways (such as a gutter) and where you apply fertilizer.

Reset your lawn mower

Sharpen mower blades, and set them up to 3 inches. Tall grass can grow deeper roots than short grass so even if you’ve been mowing low up to this point, retrain your lawn roots.

“Letting your grass grow longer means less watering, mowing, and improved root depth (and thus, water-use efficiency),” Water Wise Utah says.

A long, strong lawn helps eliminate weeds and requires less fertilizer.

Go organic

Improve your soil’s fertility by relying on natural resources, like a compost heap, to use on your lawn. Instead of throwing away grass clippings when you mow, spread them back on to “recycle” your grass, a process called grasscycling.

“Grass clippings are over 80 percent water, so they decompose quickly and release nitrogen and other nutrients back into the lawn and soil naturally, thereby improving lawn quality,” Home Composting Made Easy says.

As with fertilizer, you should sweep any grass clippings from the sidewalk or driveway to your lawn so they don’t end up in the stormwater.

You can also find organic fertilizer.

Test your soil

You may be adding nutrients to your lawn it doesn’t need, so consider performing a soil test that will tell you the nutrient levels and texture of your soil.

“Many soils along the Wasatch Front are naturally high in phosphorus and potassium,” horticulturist Duane Hatch writes. “With the regular use of composts or manures, many gardens will have adequate P and K levels. Over fertilizing can lead to salt and micronutrient problems.”

The Utah State University Extension outlines a fertilizer program for your yard, so you can fertilize appropriately instead of using a one-size-fits-all approach that could lead to more fertilizer unnecessarily infiltrating stormwater.

Replace your lawn

Reduce your need for fertilizer by reducing or eliminating your lawn. A bonus to this method is you’ll save time on yard work. In addition to decorating with rocks and mulch, you can design a garden with plants native to the area.

Salt Lake County Stormwater Coalition manages and maintains our Salt Lake County waterways. To learn more about protecting our waterways, check out