Digging the Rain Garden

Thanks for guessing at my post the other day called Digging a Hole. Creative title right? Nan of Gardening Gone Wild, Tina of In the Garden and Gloria of Pollinators-Welcome all guessed right, it’s a rain garden. Our driveway is a slope and at the bottom of it is an area that collects and pools water after each rain. Rain gardens are a good solution for dealing with water runoff problems. They help to filter out the chemicals that run off our streets and driveways before the water enters our water supply. To do this rain garden I’ll need to construct a French Drain. If you would like to look back I mentioned the French drain I was planning on building in my post called The First Step to Recovery… That post also contains a picture of the drainage issue.

To review briefly I’ll place a layer of gravel in the trench I dig. Then I’ll place a perforated pipe through the trench toward the rain garden area. I’ll cover it with gravel, then landscape fabric, then top the planting areas and grass area with soil. The area next to the driveway I’ll top with decorative gravel. The landscape fabric will keep the dirt separate from the gravel which will improve drainage.

Now the fun part!
To me the fun part is putting in the plants for the rain garden area. I plan on the garden itself to be slightly higher (3″-4″) than the surrounding ground surface. This will help to define the bed a little more and give the plants a little more soil to root through. I need plants that like water but can tolerate drought. Kind of contradictory but believe it or not something comes to mind: ornamental grasses. This past fall I rescued a Calamagrostis x acutiflora ‘Karl Foerster’ (feather reed grass) and a Miscanthus sinesis ‘Zebrinus’ (Zebra Grass) from the big blue box home-improvement store for less than five dollars. I divided the Miscanthus into four plants, two of which are in my bird bath garden and the other two are eager awaiting homes. I’ll let these three plants find refuge in the rain garden. In addition to those two grasses I am considering a fountain grass of some sort. I’ll figure that out sometime this spring. The grasses can absorb a lot of moisture from the ground and tolerate our heavy heat in Tennessee. A great companion plant to the ornamental grass is the old standard and favorite rudbeckia. Black-eyed Susans, with their dark centers and yellow petals, would look great mixed in with ornamental grasses. I also have my eye on a particular annual salvia called Salvia splendens ‘Flare.’ This is an annual salvia (possibly a tender perennial) that sends up a red flower spike around 18 inches tall. I’m also thinking of some Zinnias since those are nearly foolproof!