It seems a bit odd to be going on about excess rain water when half of the country is in a terrible drought. Here though, we’ve had some severe rain storms recently, ones that leave huge standing puddles on the Del Ray sidewalks and flooding elsewhere. Some clever homeowners, as well as staff and parents at our neighborhood elementary school have planted rain gardens to harness the storm runoff and keep the contaminated water from going directly into the sewer system.
What are the defining characteristics of a rain garden?
- Has plants perfectly suited to the volume of water and the chemical make-up of stormwater runoff (excessive nitrogen and phosphorus).
- Can filter the water as it soaks into the subsoil.
- Slows erosion by taking up a lot of the water before it gains momentum while flowing downstream.
- Usually includes a range of deep-rooted, native plants that can withstand dry conditions that exist after the drainage occurs, as well as more “swampy” conditions.
The School Rain Garden
When it rains, the water gushes off of the roof from the overhanging spout that you can see in this photo. This elementary school rain garden retains the water after it rains.
One idea was to install a rain barrel under the “waterfall” but the barrel would surely overflow too. So, the school district landscape designer, Wendy, came up with the clever plan to establish a rain garden.
Parent volunteers installed wooden raised borders to hold the water in the garden. Wendy made the following plant choices:
- Swamp milkweed
- Joe-pye weed
- Native azalea
- Sweetspire (shrub)
The school “green team” did the planting as a classroom activity.
The garden will eventually serve as an educational garden with signs and lesson plans tied to it. The main thing is that it’s beautiful to behold.
Rebecca’s Rain Garden
Rebecca planted her rain garden in a spot in her front yard where it gets sopping wet when it rains. The lawn is graded from the corner of the house down toward the storm drain in the street. Who knew such a dainty flower garden is doing so much work keeping our city water supply clean.
Her garden is a new addition to her yard, so the plants will take some time to become established. In addition to some succulent varieties, she planted:
- Novi belgii
- Iris (mini)
She bought all of her native plants from Nature by Design. You can also see the way the garden tapers off to the side into a point lined with rocks. The water will slow down there as it flows from the house.
Rain Garden How-To Resources
Rebecca learned how to design and plant her rain garden using resources from the Fairfax County Master Gardeners Web site. The Northern Virginia Regional Commission also lists workshops on designing and building rain gardens and choosing plants, and includes links to more local resources.