August 26, 2008

Rain (only) gardens: a plant palette and potential stormwater management

Garden designer Brandon Tyson’s curbside “rain-only garden” is featured in Pacific Horticulture’s Jul/Aug/Sep 2008 issue. Unfortunately for readers, the magazine does not provide an address for the Berkeley, Calif. garden. Also, the article is only available in print and I cannot borrow the issue from the library so could not include photographs. Tyson’s plant palette for the Berkeley, Sunset zone 16/17 garden includes yuccas, agaves, terrestrial bromeliads, succulents, palms, ferns, and daisies. Here is the list provided by Pacific Horticulture: Agave ‘Sharkskin,’ A. ‘Felipe Otero,’ A. victoria-reginae (below), Brunsvigia josephine, Chamaerops humulis ‘Algerian Grey,’ Chelianthes lindheimeri, Dudleya thraskiae, Dyckia ‘Jim’s Red,’ Echeveria ‘Fleur d’Or,’ E. ‘Green Goddess,’ Gazania ‘Christopher Lloyd,’ and Yucca rostrata. Tyson on his rain-only landscape project,

It’s been said that anyone can create a beautiful spring garden. It’s the same with watering. Anyone can create a garden using irrigation; I wanted to try something beautiful without it.

Source: Wikimedia Commons; right, Echeveria derenbergii, Wikimedia Commons

And a rain (only) garden provides more than beauty. It can manage stormwater runoff, by capturing potential runoff and directing it into the soil and local water table. The 28-year old Center for Neighborhood Technology in Chicago has developed a stormwater program called Green Values Stormwater Toolbox. The toolbox calculator generates improvement scenarios based on two major “green interventions” – all downspouts drain to rain gardens and green roofs – and site statistics. The calculator also provides cost details.

The first green intervention includes the replacement of one half of lawn with native landscaping and porous pavement is installed on driveways/sidewalks/other non-street pavement. The two sub-categories of the green roof intervention are the provision of tree cover on an additional 25% of the lot and the replacement of stormwater pipes with drainage swales. In addition to green interventions, several site statistics are collected including the type and number of lots (“single family home, urban” vs. “new development, suburban”), average number of trees on lot, average impermeable area, soil type, and the real discount rate. View the results for an urban single family home on 0.2 acres that utilized all the elements of the first green intervention.

The difference between the conventional system and the green intervention(s) you chose decreases the total 20 year life cycle costs and increases benefits by $1,410! This strategy reduces peak discharge by 34%.

The Low Impact Development Center provides directions for designing a rain garden as well as templates for New Jersey and West Michigan. In "Rain Gardens: Sustainable Rainwater Management for the Garden and Designed Landscape," Nigel Dunnett and Andy Clayden chronicle the historical development of rain gardens as well as define and illustrate rain garden designs and functions. There are numerous East Bay rain gardens, some of which are featured on the Blue-Green Building website, like the "natural" area Tyson Tule Ponds in Fremont, the detention pond in Grinnell Glade in Berkeley (see Sustainable setting for scholarship), the Kaiser Center greenroof in Oakland (built in 1960!), and the swales at St. Joseph Cemetary in San Pablo. Blue-Green Building is a project of Friends of Five Creeks, restoration volunteers for creeks in North Berkeley, Albany, Kensington, and southern El Cerrito and Richmond.

For photographs of a Tyson garden, read the Times story about the Moorish garden he designed in Sonoma Valley. This is not a rain-only garden as evidenced by the active fountains and a runnel (the one above is located in Sevilla). Philip’s Garden Blog has extensive coverage of the garden Tyson designed for Linda Hothem of Sausalito. If you are a Berkeley gardener, you’ll appreciate Michael Pollan’s essay, “An American Transplant, about a “somewhat pinched New England gardener” learning to garden in coastal California where plants from the five Mediterranean zones and more grow vigorously (irrigation required for some).

Aside: You may have noticed that local ecology has removed the link to its virtual bookshop. We felt it was contradictory to promote local while administering a non-local bookstore. Despite the closure of Cody’s, Berkeley “is still a great bookstore town.” Read about the city’s bookstores as well as the ones in Oakland in Joe Eaton’s special to the Berkeley Daily Planet.

2 comments:

  1. Thank you so much for visiting my blog and for recommending the Bradner Gardens in Seattle. I am planning a field trip there for next week with a friend!

    Your site is wonderful, I just added it to my blogroll so I can read all the older posts. I used to live in SF and could not fathom gardening on the street there (Duboce Triangle) but the Mission gardens on your site are inspiring. I'm hoping more people will try this sort of thing in cities.

    - Karen
    http://greenwalks.wordpress.com

    ReplyDelete
  2. I thought you might enjoy some pictures of our garden.
    Cheers,
    Amy
    http://cyrus.hypershots.com/gallery/0001x9mw

    ReplyDelete

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