By Corrina Parnapy
The 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, there is an increasing concern from excessive nutrients flowing off of lawns, impervious surfaces and farmland, thus impacting our aquatic ecosystems. Since 2012 in Vermont, homeowners should be 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.
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 of the land and into local bodies of water. Phosphorus should not be in fertilizers applied, but nitrogen also has impacts.
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 trigger a toxic algal bloom in certain species of cyanobacteria (blue-green algae).
When 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 damage sensitive native plant species and alter the soil chemical composition, allowing for invasive species to take hold. Excessive nitrogen can cause the depletion of calcium, phosphorus and magnesium in the soil.
What can we do to maintain our lawns and still protect our natural resources?
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 3-4 inches. Never cut off more than 1/3 of the blade 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 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 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 our natural resources. To learn more about urban conservation initiatives and urban and community agricultural initiatives, please visit the WNRCD website at: winooskinrcd.org
Corrina Parnapy is the district manager of the Winooski Natural Resources Conservation District, which encompasses Chittenden and Washington counties, as well as parts of Orange County.