The speaker was Laurie Fox, horticulture associate with Virginia Tech and one of the authors of the book, Best Plants for Hampton Roads: A Landscape & Garden Companion, which of course I bought...can't have too many gardening or quilting books!
Laurie talked about the structure and function of this type of garden. Some things I learned:
- A "rain garden" is a man-made depression in the ground forms a "bioretention area" by collecting water runoff and storing it, permitting it be filtered and slowly absorbed by the soil.
- A nutrient removal or "filtering" process takes place as the water comes in contact with the soil and the roots of the trees, shrubs and other plants. This process promotes improved water quality.
- The rain water is ponded in the lowest level of the rain garden, and gradually "percs" through to the groudwater below, cleaner that when it fell through the atmosphere.
- It's best to plant the rain garden with more native species to minimize the need for chemical fertilizers.
The wiki site actually has some good information- http://en.wikipedia.org/wiki/Rain_garden
This is also a good reference, but takes awhile to load- http://www.dnr.state.wi.us/org/water/wm/dsfm/shore/documents/rgmanual.pdf
I will definitely think about this concept as I work around the areas that my gutters and driveway drain to...