By Sandra Tarpinian
The impacts of climate change on our local weather patterns — more days over 90 degrees and flash droughts punctuated by flash flooding — result in more stormwater flowing into our streams, rivers, and the Chesapeake Bay and carrying with it more fertilizers, pesticides, and debris. We now pay fees for the City to upgrade essential stormwater drain infrastructure to carry that water away. But what if we could keep more of that water on our properties in ways that would help slow, filter, and absorb it into the ground rather than running it into the street? We can, by adopting landscaping practices that provide long-term, sustainable solutions to stormwater management.
For decades, a green mown lawn has been the standard for home landscapes. Lawns are useful for play spaces, entertaining and pets. But turfgrass now covers more than 40 million acres in the continental U.S., making it the single largest irrigated crop in the country. Typical turf lawns, often made up of non-native grass species, do not provide food or nutrition for wildlife (or humans!) They require enormous amounts of fresh water and chemicals to maintain. They are shallow-rooted and absorb very little water into the ground, and the emissions from mowers, leaf blowers, and other lawn equipment contributes to climate change.
Ready to reduce the size of your lawn this year? Here’s how to start:
Step 1: Assess your lawn. Do you need lawn for use by the kids or the dog? Are there areas where the turf doesn’t grow well, or a slope that is difficult to mow? Is there a tree that has turf surrounding it where you could create a mulched bed?
Step 2: Track the flow of water onto and off your lawn during a heavy rain. Where is water leaving your property and running into the street or onto an adjoining property? Is water settling in an area every time it rains? These areas could be ideal locations for a new plant bed or a rain garden to better control stormwater runoff. If water does not drain from an area within two days, the soil is likely compacted. Add more plants to beds uphill from such low spots, particularly in beds that roof downspouts flow into.
Step 3: Plan your lawn removal project over time. Almost every lawn has some possible place where turf can be removed and replaced with a mulched bed, ideally with a new tree or a few native plants, grasses, or shrubs installed. Remove lawn in manageable tasks that are reasonable for your time and energy. If you plant new trees or plants, you will want to factor in caring for them properly.
Step 4: Remove turf. One simple method is to define your area, lay down thick layers of newspaper, and cover the area with several inches of mulch. Over the winter the grass will die, and the newspaper will decompose. Another method is to dig up the turf, turn it over so roots face up, and cover the upside-down turf with several inches of mulch. By the spring, the soil should be ready to work. Turf is often planted on very compacted soil, so it is best to do a soil test when you are planting a new area. Soil test kits are available at most area libraries. The soil may need to be amended with leaf mulch or compost before you plant.
Step 5: Adopt new habits to maintain remaining turf. The following practices can also help with stormwater retention by improving the soil structure under our lawns.
Set mower height to 3 inches or higher: Taller turfgrass slows the rate of runoff and will produce a deeper and denser root system. Setting the mower higher means mowing less often, too.
Retain grass clippings and chopped leaves on-site: A mulch-mower is ideal for retaining and spreading clippings on your lawn. The clippings decompose quickly, provide important nutrients for your lawn, and settle to create an organic layer on the soil that encourages stormwater infiltration.
Reconsider broadleaf. Clover provides nitrogen to turfgrass. Including clover or letting native violets take hold in your lawn creates a low meadow for bees and insects.
Step 6: Plant locally native trees and native plants. Tree leaf canopy slows the rainwater as it falls, and tree roots soak up gallons of water. Trees also store carbon, removing it from the atmosphere. Native plants build deep root systems that absorb and filter stormwater, build the soil structure, and prevent erosion far more than turf. Native plants and trees are adapted to our climate and require little water, fertilizer, or maintenance once they are established. And they feed the pollinators, who feed us!
In our area, there are now more sources for native plants and a great resource for learning more about native plants and trees is PlantNOVA.org. Learn more about rain gardens by searching rain garden design at fairfaxcounty.gov. And check out the RainSmart program at VPIS.org to find out how to qualify for rebates when you eliminate lawn and install planted mulched beds, rain gardens, and/or rain barrels.