Beanstalk 2013

WANTED: thrill-seeking gardeners with a love of heights. Experience washing skyscraper windows a plus.

Such an ad might appear in Portland, Oreg., by 2013. Thanks to government stimulus funds, the city's main federal building will be renovated with giant plant-bearing trellises down its western side. These "vegetated fins" will shade the building in summer and let sunlight through in winter. Plus, it means hyper-local produce in the middle of a city.

Vertical farming projects not unlike this one were voted among TIME Magazine's 50 Best Inventions of 2009:

Real estate — the one thing we're not making any more of. That might be good news for landlords but not for the world's farmers, who have finite cropland to feed a growing global population. The answer: build up by farming vertically.

The ultimate vertical farm is the kind proposed by Dr. Dickson Despommier of Columbia University -- 30 floors of grains, vegetables, and fruit inside a skyscraper, complete with water recycling, hydroponic systems and wind turbines on the roof. For now, cost is the major barrier, with some estimates in the billions.

Valcent Products Inc. is piloting a tiny version of Despommier's dream. But the vegetated fins in Portland (even if they're outside and not inside the building), which will cost $133 million, might give a better idea of the potential for serious vertical gardening.