From todays DJC
June 11, 2012
From paved to paradise: Garage roof now home to the UpGarden
By LYNN PORTER
Journal Staff Reporter
When gardeners at Seattle's newest P-Patch look around they see the Space Needle, Queen Anne and other downtown neighborhoods.
This is no ordinary garden: The 30,000-square-foot space sits atop the three-story Mercer Garage at 300 Mercer St., just north of Seattle Center.
“In a dense neighborhood like Queen Anne it's really the only spot left to put a P-Patch,” said Eric Higbee, whose Seattle-based landscape architecture practice, Kistler|Higbee Cahoot, designed the garden.
City officials say this is the first publicly accessible large-scale community rooftop garden in the U.S. “It's a total transformation from the parking lot that it once was,” Higbee said.
The garden opened this month after volunteers spent months building it on a tight budget of $150,000. The cost was $5 per square foot, thanks to free labor and less expensive materials.
The clearance of the garage wasn't high enough to bring in dump trucks, so soil was trucked to the site and blown onto the roof with hoses connected to the trucks.
The soil itself also posed a problem.
The garage roof can hold 40 pounds per square foot, but wet soil can weigh 100 pounds per square foot or more, Higbee said.
The design team, with help from structural engineers at Perbix Bykonen, decided to put soil in raised wood terraces with wide paths between them. This gives gardeners enough soil for planting but keeps the weight below the garage's structural limits. Potting soil was used because it is a bit lighter than topsoil.
A 1960s Airstream trailer found cheap on Craigslist houses the tools. A crane had to be used to set it on the garage because of the clearance issue.
The garden has about 100 plots, communal space, and room for both ornamental and pollinator plantings.
Design and construction volunteers get priority for the plots, said Laura Raymond, levy projects coordinator for the Seattle P-Patch program.
Other team members are Nicole Kistler, a landscape designer and public artist with Kistler|Higbee Cahoot; rooftop vegetable design/build consultant Seattle Urban Farm Co.; and Newton Building and Development, which installed posts for the terraces.
Funding came from the 2008 Parks and Green Spaces Levy. The levy called for developing community gardens in four areas of the city, including Queen Anne, Raymond said. Upper Queen Anne has gardens, but Lower Queen Anne, in the dense urban core, does not.
Much of the publicly owned space in Lower Queen Anne has buildings or parking lots on it, Raymond said, so the city got creative and came up with what is being called the UpGarden.
Mercer Garage covers almost two city blocks, and is seldom used to capacity, Raymond said. Cars can still be parked on the roof because the garden doesn't take up the entire space.
The city has about 80 P-Patch community gardens, and may develop more on rooftops downtown given the high demand by condo and apartment dwellers who want to get their hands in the dirt, she said.
Developers also have taken note. In the last 10 years, more multifamily buildings downtown have included roof gardens, Raymond said.
Being up high, the UpGarden gets more wind and will be hotter and colder than gardens at ground level, so it's a bit tougher to grow most vegetables, Higbee said. But the great sun exposure means slugs and moles are less likely.
If you want to see the city-owned garden, mosey on up sooner rather than later.
Seattle Center's redevelopment plan calls for the garage to be torn down in three to five years.