So, what’s a rain garden?
• Appealing landscape ideas for homeowners and Property Owners Associations.
• Allows collection of stormwater and infiltration.
• Plants and microbes do the work of pollutant removal.
• Can be attractor for wildlife such as birds and butterflies.
• A natural way to irrigate.
Where do we put the rain garden?
• Between rainfall runoff “source” and “destination”.
• We want to intercept the water before it reaches surface waters or low spots!
• Gutters and downspouts help direct rooftop runoff flow.
• Driveway and sidewalk edges can also make good locations.
• It’s important to watch how water flows during a storm event!!!
• Install your rain garden more than 10 ft. from building foundation, and more than 25 ft. from a septic system drainfield.
• Avoid shallow water tables (less than 18 in. deep).
• Away from utility lines.
• Ensure no buried cables or pipes in the excavation area.
• In full to partial sun, if possible.
What size should the rain garden be?
• Determine the area of impervious runoff source (rooftops + sidewalks + driveway areas).
• Rule of thumb: estimate the size of your rain garden based on soil types:
Sandy soil (well-drained) = 20% of impervious area.
Loamy soil (poorly-drained) = 20-60% of impervious area.
• May be limited by the space you have, but smaller is easier!!
• The excavated area should be 6-8” deep.
• The area should be typically 8-10 ft. wide in the direction of runoff flow.
• Try using a kidney bean or half moon-shaped layout with the inner curve of the area facing the runoff source!!
How do I know if it’s in a good spot?
The ability of rain water to drain is important for your rain garden location:
• A simple “perk” (percolation) test can help you to decide:
1. Dig a hole about 6 inches deep and wide
2. Fill the hole to the top with water
3. Check the hole 24 hours later – if the water is gone, you have an ideal rain garden location, otherwise, consider a backyard wetland!!
What kinds of plants should I use?
• Hearty species with a range of drought and wet condition tolerance.
• Options include small trees, shrubs, perennials, and grasses.
• Please use native species!!
• Plants that attract butterflies and hummingbirds.
• A plant list is available – contact the Beaufort County Clemson Extension office.
How much will my rain garden cost?
• For an 8 x 20 ft. garden:
• Plants = $200 (retail; cheaper if you use wholesale or transplanted).
• Soil mix and mulch = $200 (retail; cheaper if you use bulk or fill).
• Labor = free (don’t forget to use your friends).
• Total = $400 (~ $2.50 per sq. ft.)
• Protecting water quality = PRICELESS!!
Please visit the websites below for a wealth of information on smart Lowcountry landscaping and to learn the things all property owners can do to protect water quality and our delicate Lowcountry environment:
www.clemson.edu/cyn Clemson’s Carolina Yards and Neighborhoods program has practical and comprehensive information on how to irrigate and landscape responsibly.
http://www.clemson.edu/extension/hgic Clemson’s Home and Garden Information Center is the resource for all of your horticulture and landscaping questions.
www.clemson.edu/extension This website is the home base for Clemson’s statewide Extension Service system.
www.clemson.edu/beaufort Beaufort County’s Clemson Extension Service office can be found at this website. Or contact their office at (843) 470-3655.