Did you know that lawns cover nearly 10% of the Chesapeake Bay watershed? And turf grass covers a much higher percentage of the land in many urban and suburban areas. Unfortunately, all of this lawn is a major source of water quality problems in Reedy Creek as well as the Chesapeake Bay.
Why do lawns have a negative impact on water quality? Consider a lawn that is managed by frequent mowing and always kept cut at a low height. During the hot and dry weeks of the summer, the lawn dries out and the soil becomes hard. When a thunderstorm finally provides some relief, much of the water from the hard-driving rain runs off the lawn because the ground acts more like concrete than soil. So the first consequence of lawns is that they can contribute a lot of stormwater that reaches Reedy Creek very quickly. In turn, this leads to streambank erosion and harms aquatic life. Second, as stormwater runs across a lawn, it can pick up a variety of pollutants (e.g. soil particles, fertilizers, pesticides, herbicides, dog poop) that damage Reedy Creek as well as the James River and Chesapeake Bay.
What can you do to prevent degradation of Reedy Creek from lawns? The first step is to manage your lawn to minimize potential impacts to water quality. Do not cut the grass on a strict schedule. Mow the grass when it reaches a height of approximately 4 inches and use the highest setting on your mower. Taller grass shades out weeds, promotes deeper root growth, and reduces evaporation. That means the lawn will not turn into “concrete” as quickly and will do a better job of infiltrating stormwater (i.e. reducing polluted runoff). To minimize pollutants, eliminate the use of toxic chemicals; quickly repair any bare spots that could release soil particles; and use the minimum amount of fertilizers, preferably organic fertilizers such as compost and mulched/shredded leaves. (Now that the city is not picking up leaves, this is a great way to make them disappear!) Organic fertilizers provide nutrients over a long period of time as well as improve the soil. Lastly, leave the grass clippings on the lawn to recycle the nutrients and help build the soil.
The second step you can take to prevent degradation of Reedy Creek from lawns is to replace unnecessary grassy areas with native plants that have existed in the Richmond area for millennia. Any combination of native grasses, perennial flowers, shrubs, and trees will provide greater environmental benefits than lawn. This is because the root systems of these plants grow much deeper into the soil than turf grasses, sometimes reaching depths greater than ten feet. These plants can reach all of the water and nutrients they need once established. No need for watering or fertilizers or toxic chemicals that can runoff into Reedy Creek.
There is one more critical benefit of replacing lawn areas with native plants. Lawns are virtual “biological deserts” – very few insects, birds, amphibians, etc. Have you noticed that the most frequent birds in most urban yards are European starlings and house sparrows? Both species are native to Europe and don’t even belong in Richmond. By contrast, areas with native plantings will draw a host of native birds including gray catbirds, brown thrashers, rufous-sided towhees, and white-breasted nuthatches – not to mention winter visitors like white-throated sparrows, juncos, and cedar waxwings. In short, native plants provide all of the resources needed to support a thriving food web from butterflies to bees to birds.
For a humorous look at lawns, check out the following short piece: http://www.wildlifegardeners.org/forum/dead-lawn-society-healthier-choice-gardeners/8124-st-francis-explaining-grass.html.
For a more detailed exploration about the benefits of replacing lawn with native plants, visit the following website: http://content.yardmap.org/learn/removing-lawn-to-make-way-for-more-habitat/?utm_source=Cornell+Lab+eNews&utm_campaign=d15849e6ff-EMAIL_CAMPAIGN_2018_02_09&utm_medium=email&utm_term=0_47588b5758-d15849e6ff-278116725