Tacoma Goodwill's garden wall is a new city icon

VERTICAL GARDENS are literally climbing in popularity, and Tacoma is out front with a green wall designed by the man who invented them. French botanist and artist Patrick Blanc's 800-square-foot vertical garden for the Goodwill-Milgard Work Opportunity Center was unveiled in September. It graces the entrance of an imposing new building designed by BCRA Architects, and is sufficiently large and fluffy to be clearly visible from busy Tacoma Avenue.

Blanc visited the City of Destiny last summer to supervise the wall's installation, and gave a talk about his work at the Washington State History Museum. Just picture a slip of a green-haired man enthusing about bringing nature back to cities while wearing slim green pants and sporting long, talon-like green fingernails.

The Goodwill's planted wall is as unusual and flamboyant as its designer. Thousands of multihued foliage plants run in diagonal ribbons across its 20-by-40-foot surface. Ferns and shrubs, heucheras and hellebores billow out from the wall. Liriope and Japanese forest grass sprout as if by magic. Out of the 96 different kinds of plants, a few, like the epimedium, are struggling. But most appear to be thriving, including plants like yews, andromeda and iris so unlikely to be growing high up in the sky you can't quite believe your eyes.

On a trip to Malaysia as a teenager, Blanc was intrigued with plants growing on rocky cliffs in little or no soil. He built his first vertical garden 30 years ago for a science museum in Paris, and has been perfecting his system ever since. In the past year, Blanc designed his largest U.S. green garden for the Drew School in San Francisco, and blanketed the exterior of London's historic Athenaeum Hotel in plants.

What alchemy encourages plants to grow sans soil? David Western of Teufel Landscaping, the local company responsible for the installation, explains the green wall's sandwich-like construction. A double layer of felt is mounted on top of PVC piping, which is layered on top of a metal frame attached to the building. Slits are cut into the felt to make little planting pockets. "We knocked some of the soil off 4-inch plants, then stuck the roots into the double felt layers, and added a few staples to hold the plant securely," explains Western. Unbelievably, even woody plants are planted this same way, their roots surviving (so far, anyway) in about a half-inch-thick layer of felt.

A drip irrigation system runs across the top of the wall and in a horizontal band halfway down. Water and fertilizer from the system "bleed" through the felt to keep the plants perpetually moist and nourished. There's a freeze switch to stop the irrigation on the coldest days of winter so the garden doesn't turn into a solid wall of ice.

The day I visited, slimy green muck dripped down between the plants that hadn't yet filled in. "Patrick wants algae to grow on the felt," says Western. "It'll eventually turn to moss." Such conditions supposedly mimic the mossy cliffs where many of these plants grow in their native environments.

I was almost scared to bring up the topic of maintenance; won't some plants grow too vigorously while others languish and die out? Western assures me that Blanc is confident in all the plants, having used them many times before. The plan is to prune the wall just twice a year, a task accomplished in a cherry picker.

How did a nonprofit in Tacoma end up with a living wall so astonishing it might be dubbed the Cirque du Soleil of the plant world? "After construction of the new building, we ended up with a big, blank wall," says Matthew Erlich of Tacoma Goodwill. They were considering a mural, when one of the architects showed Goodwill CEO Terry Hayes a photo of Blanc's work. "That was it; we had a signature piece for our new building," enthuses Erlich. "Our green wall is a new iconic image for Tacoma, along with the dome and the bridge of glass."

The Goodwill-Milgard Work Opportunity Center and its green wall can be found at 714 S. 27th St. in Tacoma (www.tacomagoodwill.org).

Valerie Easton is a Seattle freelance writer and author of "The New Low-Maintenance Garden." Check out her blog at www.valeaston.com.