By Julie Chai, Sunset associate garden editor

We just can’t get enough of vertical gardens and, last week, I met the man who invented them. Patrick Blanc was in town working on a 1,700 square foot vertical garden for the Drew School in San Francisco, a project that will be his biggest in the U.S.

Having worked for nearly three decades as a botanist for a Paris-based research organization, Blanc travels the world studying plants. He recalled taking a trip to Malaysia when he was 19, and having a lightbulb moment: He saw plants growing from rocks, without soil, and that inspired him to create a soil-less systems for growing plants. He built his first large-scale vertical garden for a Paris science museum in the late ‘80s, but “nobody was interested,” he says.

That quickly changed. A few years later, at a French garden exhibition, Blanc built three living walls—and people went crazy over them. He’s since created countless vertical gardens around the world.

Bonnie Fisher, principal and landscape architect with Roma Design Group, the architecture firm behind the Drew project, says they wanted to work with Blanc because “he brings science and art together—that’s very compelling for a school in particular. When you see Patrick’s work, you see there’s another entire way of dealing with vertical surfaces that hasn’t been done before. We can see this is going to be a project that’s transformative to the entire city.”

I shopped with Blanc at Flora Grubb Gardens while he gathered ideas for the Drew project’s plant palette. This was his first trip to San Francisco, and he noted our enviable climate that makes this a playground for gardeners and allows us to grow a huge diversity of plants. “Side by side you see plants from desert and tropical climates," he says. "There are not too many places like this in the world.”

But he also noted the absence of natives in our landscapes, and plans to incorporate native Dudleya, penstemon, ceanothus, and mimulus in the project. “It’s important to save California natives because you have plants that need to be protected," he says.

And on a larger level, he hopes his work will help green otherwise gardenless cities around the globe, saying, "Now, more than half the world is living in urban environments, so it’s very important to have patches of nature inside." 

This rendering of the Drew School vertical garden (courtesy of Roma Design Group) gives a glimpse of what you'll be able to see in person at California and Broderick Streets in San Francisco. The project's scheduled to be complete by the end of 2010.