Greener Lawns and Cleaner Water

By Linda Patterson, Land-Use Planning & Water Quality Educator
April 14, 2020

We greet spring as buds swell on the trees and days get warmer. These changes can reassure us in the midst of such uncertain times.

Lawn and garden care become an appealing activity for many of us—a way to get outdoors and welcome new life. Lake Champlain Sea Grant and our many partners promote easy ways to help minimize stormwater runoff, protect water quality, and keep soils healthy, all while we enjoy mowing, digging in the dirt, and planting.

Reports of polluted water, algal blooms, and beach closures fill the news in recent years. Maybe you have had to cancel plans to spend the day at the beach because of a bloom or boil water for a time. Stormwater runoff that starts as rain and snowmelt on our yards is the source of some of this pollution. 

Do you know that something as simple as how we mow our grass can help prevent this pollution from getting into our lakes and streams? That’s right: cutting the grass at three inches (instead of one or two inches) and leaving the clippings on the lawn can help the grass absorb and filter stormwater. It’s like a natural water treatment system!

Here’s how it works:  the longer the grass, the longer the roots. The longer the roots, the more air spaces in the soil to absorb water. Longer roots reach deeper during dry spells, so lawns are less vulnerable to drought. Watering our lawns uses a lot of water, and much of it evaporates instead of sinking into the ground. In fact, lawn irrigation in the United States accounts for almost 30% of total water use!*

Longer grass provides another benefit: the grass blades capture more energy from the sun. That helps make the grass stronger and creates more shade for the soil, which helps reduce evaporation.

When we leave grass clippings instead of bagging them, we actually create healthier soil. The clippings break down into organic matter and become fertilizer that feeds the grass with the same ingredients as the chemicals you buy in the store: nitrogen and phosphorus. Only, it’s natural!

The organic matter makes the soil act like a sponge, absorbing and filtering stormwater. Healthy soils increase the lawn’s resistance to disease and pests. Not only does your lawn need less chemical fertilizer; it also needs less chemical insecticide and fungicide.

There are more ways you can help reduce stormwater runoff, attract pollinators like bees, butterflies and moths, and feed the birds, all at the same time. Use native plants in your garden and replace some of your lawn with native bushes, trees, and groundcover.

Native plants have longer roots, absorbing more stormwater than grass and protecting the land from erosion. Native plants also support insects and seeds specifically evolved to feed our local birds.

Learn more about Lake Champlain Sea Grant, our partners, and campaigns to promote these lawn practices. You will find links to articles, local resources, and programs such as Lawn to Lake, Raise the Blade, and Don’t “P” On Your Lawn, all of which will help you manage your lawn and garden in ways that protect water quality and support our ecosystems. You can also visit our Facebook page

Lake Champlain Sea Grants' partners on these campaigns include: Composting Association of Vermont, Cornell Cooperative Extension, Lake Champlain Basin Program, Lake Champlain Committee, UVM Extension, Vermont Department of Environmental Conservation, and Vermont Natural Resources Conservation Service.


*Outdoor Water Use in the United States. Water Sense. August 2008. EPA-832-F-06-005 (PDF)