Ok, the side yard project is a vegetated swale with check dams rather than a true rain garden. Side yards, even if they are flat, do not typically have the space to store all the rain water from the roofs. In this case the water is damed up in the channel that runs down the slope between the houses. The water that does infiltrate helps nurish the plants (they can tolerate the momentary ponding) and then any remaining water is let out more slowly than it would have occured otherwise.
The other idea this project tests is vertical storage. Basically taking draintile to create a vertical column where water can be stored. It increases the capacity to store water while increasing the infiltration. After attempting this, I've realized one really needs a deep hole for this to work efficiently. Mine are only a foot and a half deep. It is still a great idea for small spaces.
* Wild Ginger
* Hostas
* Sedum
* Liriope (Monkey grass)
* Black-eyed Susans
* Sedges
So last June I embaked on a 12 hour design binge to decrease the amount of mowing and watering in my side yard. The design was entered in the
Air Pollution Control Board Low-Maintenance Landscape Competition. And they gave me the go-ahead to make it happen! So now I'm in the midst of "building" the garden...