When fertilizing the lawn, don’t forget the environment

Winter’s over, weather is warming and it is once again time to think about our yards.

There is nothing like a barefoot walk through a soft lawn. The mixture of clover, grasses and low-growing beneficial plants are not only pleasing to the eye, but lend to conservation practices that improve water quality protection.

In the Lake Champlain watershed, which includes the Stowe area, there is an increasing concern from excessive nutrients flowing off lawns, impervious surfaces and farmland, with impacts on our aquatic ecosystems.

Since 2012 in Vermont, homeowners should have been following the no-phosphorus rule when fertilizing lawns, unless a professional soil test has been conducted on the soil, determining that it is needed and/or the lawn is just being established.

Grasses, like other plants, need nutrients within the soils to grow. These nutrients can be provided by implementing lawn care best management practices. Recent surveys of soils within Vermont lawns indicate that most lawns do not need any additional fertilizers.

There is a tendency when applying fertilizers to think more is better. This results in excessive nutrients flowing off the land and into local bodies of water. Since phosphorus should not be in fertilizers applied, I will focus on the impacts of nitrogen.

Excessive nutrients that enter our waterways feed algae. When the algae then “blooms,” it can shift the pH of the water, decrease oxygen levels, cover fish breeding habitat, clog intake pipes, cause taste and odor issues, discourage recreation, lower property values and — when bacteria feed on dead algae — cause fish kills from decreased oxygen levels.

The nitrogen in fertilizers can actually trigger a toxic harmful algal bloom in certain species of cyanobacteria (blue-green algae).

When the excessive nitrogen enters groundwater, it can cause methemoglobinemia (aka Blue Baby Syndrome) in the elderly and the young. Symptoms include gastrointestinal swelling, diarrhea and protein digestion problems.

Excessive nitrogen can actually damage sensitive native plant species and alter the soil chemical composition, allowing invasive species to take hold. Excessive nitrogen can cause the depletion of calcium, phosphorus and magnesium in the soil.

With the issues of fertilizers, what can we do to maintain our lawns and still protect our natural resources? Follow lawn care best management practices, which will help you have a healthy, sustainable lawn. 

• Water your lawn in the morning; water deeply and infrequently. Grasses will go dormant and survive times of drought. There are species of grasses that don’t need frequent watering. 

• Reduce the size of your lawn. Add a beautiful native or naturalized garden that will attract butterflies, birds and pollinators.

• Leave clover in the lawn. Clover adds nitrogen to the soil naturally.

• Mow only when there is rain in the short-term forecast. Maintain the grass height between 3 and 4 inches. Never cut off more than one-third of the blades of grass and keep your mower blade sharp.

• Leave grass clippings on the lawn. Grass clippings add back nutrients naturally.

• Never pile clippings near a body of water or push them into a storm drain.

• Maintain a buffer of native species along waterways. It is recommended to have a 50-foot- buffer along streams and a 100-foot-wide buffer along lakes. 

• If fertilization is needed, do so only in the fall. Spring rains will wash the nutrients into our waterways. 

• Use species of grass that are acclimated to our climate zone. Many of the mixes that are sold require regular watering, mowing and fertilizers. There are mixes of species sold that surprisingly cost less and require limited maintenance.

There are many practices and projects that you can implement on your own property that will bring enjoyment and protect of our natural resources. To learn more about urban conservation initiatives and urban and community agricultural initiatives, please visit winooskinrcd.org. 

The Winooski Natural Resources Conservation District is one of 14 conservation districts throughout Vermont. It encompasses all of Chittenden and Washington counties, as well as Orange, Williamstown and Washington. The district relies on grants and donations to complete its conservation work. The district focuses on completing conservation projects in agricultural assistance, forestland enhancement, urban conservation and watershed stewardship.

Corrina Parnapy is district manager of the Winooski Natural Resources Conservation District.