Some years ago, our species climbed out of the trees and retreated into caves. Personally, I've never gotten over it. I miss living with plants.

Maybe it's a sign that I'm disconnected from the landscape, but I'd love to live in a house covered with plants. A house like that would help me feel part of the natural world, rather than part of technology. After all, the city is technology - it's all about human-built systems, functioning at peak efficiency to replicate those functions formerly performed by the natural world. Don't get me wrong, I'm no luddite. I like technology. But it's not what I'm all about. I'm about leaf litter, and worms, and tomatoes, and all that good stuff.


Photo by Kıvanç, shared via Flickr

I'm not alone in my desire to live among plants. Many people want ivy to grow on their homes. And not just on houses. There's something about plant-covered walls that make large buildings seem inviting, approachable. Architects call this "bringing down the scale of a building." City planners respond to this need by requiring trellises on some buildings, especially on multifamily residences (huge blocks of apartment buildings). Builders respond grudgingly. Check out the pitiful cupful of dirt at the base of the trellis at left. I feel sorry for that plant.


Photo by City of Lynnwood.

When it comes to respecting plants, architects usually don't do much better than builders. They often draw elaborate trellises on their drawings. Then they'll draw some generic plants on their drawings and refer to them disparagingly as "growy things." The plants are an afterthought. Like on the beautiful trellis below: How would a plant even get up there?


Sometimes this is just self-deprecating humor, a nod to the more specialized field of landscape architecture. But it's also a response to the dire warnings of structural engineers, bricklayers, and all kinds of other contractors: Plants destroy houses. Ivy, for example, has little feet that pulls the weatherproof outer surface off walls, exposing the wall's vulnerable interior.


Photo by moplants.com


Photo by Christian Herman, St. Louis Brick

Other plants can damage buildings in other ways Wisteria pulls structures apart. Hedges trap moisture near wood walls, causing them to rot. Roots and vines will seek out a crack, then pry it open as the plant grows. Even my favorite little mountain flower, the saxifrage, comes from the latin meaning "rock breaker."


Saxifrage photo by Brewbooks, shared via Flickr

But some innovative designers are trying to break down that barrier between garden and home. They're using new techniques that allow plants to grow directly on walls, where a highly engineered layer of construction materials protects the wall itself from the plants. Below, the Musee du Quai Branly in Paris, France.


Photo by Markhillary, shared via Flickr

Below, the Millenium Village, U.K.


Photo by Thingermejig, shared via Flickr

In other projects, the plants are held away from the building on a stand-alone metal screen. Below, the Capitol Hill Library in Seattle hopes to be completely covered in vines some day. There are several inches of air circulating between the plants and the brick wall.


Photo by Johnston Architects, Seattle

In some places, you can do it without the building. Check out the "living wall" in the photo below. I don't know how these plants get the minerals they'd normally attain from the soil. But it sure looks cool:


Photo by Thingermejig, shared via Flickr

Growing plants on the roof also helps reduce stormwater runoff and cool down overheated cities. Works equally well on big stores and little garages.


Photo by Mountain Equipment Co-op, Toronto store, shared via Wikipedia


Seattle Architect Rob Harrison's garage

I remember reading an essay by E.B. White from his collection, One Man's Meat. He had recently retired to a small Florida town near the Everglades. He described how, down there, plants thrived in every crack in the sidewalk, consumed buildings on the edge of town. In short, nature would consume this village in a heartbeat. The moment the citizenry put down their machetes, they'd be buried in greenery.


Photo by Eric I. E., shared via Flickr

There's a the old frontiersman's fear of wilderness in that observation. But I think White also admired that wilderness for its tenacity, its fecundity. Personally, I find nature's resiliency comforting. And I don't see any reason to wait for civilization to collapse before we can bring nature into our cities. Really, nature can be quite a polite houseguest. It requires so little of us. Just a crack in the wall.


Photo by Tim Parkinson, shared via Flickr

After following green roof and living wall designs for years, I got a kick out of a recent article in the Seattle Times. Perhaps this is the next frontier:


Photo by Chris Butler, Idaho Statesman

ZRecs.com cover photo by Geishaboy500, shared via Flickr.