In the wake of the global financial crisis, urban farming seems like one of the few options left for struggling urbanites. You will probably lose your job any minute and then start falling through the cracks. Repossession awaits like an undercurrent tugging at one’s sense of destiny. Banks have failed, politics has failed, the grapes of wrath have been brought out of storage. But the ground is still there, and if one starts digging, seeding, and watering, then plants will grow. Despite all of humanity’s faults and follies, nature always takes its revenge, continuing her cycles. While Occupy Wall Street shook up the capitalist miscreants for a brief season and then faded, urban farming has begun to occupy American streets, vacant lots, and rooftops as an incredibly optimistic threat to the system.

A garden normally takes time, several years, before it acquires an identity. But when you’re desperate, you just start throwing seeds and hope you will still be there to watch them grow. Looking carefully at the many urban agriculture projects on display in the U.S. Pavilion at the 13th International Architecture Exhibition at the Venice Biennale, one notices a theme of transitory gardening, some on the flatbeds of trucks, others in the cracks of pavements, some the result of guerrilla gardeners’ seed bombs. Fritz Haeg, author of Edible Estates, has been coaching Middle Americans over the past few years on how to transform their wasteful front lawns into productive orchards. He resembles a latter-day Johnny Appleseed, and many others have followed similar paths. Do all of these idealistic greeners adhere to an ecological agenda? Will their interest in farming last longer than a season? Is growing food their real objective? Frequently the answer to these questions is “no.” Urban farming often proves less cost-efficient than going to the supermarket. Many an heirloom tomato, grown by an eager civic agriculturalist, has been coaxed along with synthetic fertilizers. And the enthusiasm for hoeing and watering is sometimes just a trend that not all participants desire to continue.

But even so, why not try? Every act of planting is remedial, both on social and environmental levels. An online urban farm registry that allows farmers in San Francisco to negotiate some neighborly swapping of kumquats for tomatoes, or an organization that gathers fallen fruit and other unharvested urban edibles to distribute to food banks in Los Angeles, or a market on wheels that brings organically grown produce to Chicago’s low-income neighborhoods where fresh vegetables are rare are all initiatives that restore faith in the great social project that once was part of a national ethic—even though they seem destined to last only as long as the enthusiasm of their volunteers. American civic agriculture might appear frivolous to Cubans, who have created organopónico gardens amidst their public housing projects due to economic necessity, or to the urban farmers in the slums of Nairobi, who make money from vegetables grown in gunnysacks.

Leberecht Migge, the “Green Spartacus” of Weimar Germany, who attempted to install vegetable gardens in all public housing blocks, would have scoffed at the lack of structure in the American efforts. For the moment, it appears green for a day, as ephemeral as graffiti. One longs for the delirious commitment of Adam Purple’s “Garden of Eden,” created on a vacant lot in the Lower East Side of Manhattan in 1973 (and demolished by mayoral order in 1985). Still, the more that people get involved in urban farming, the more they will seek associations, establish rules, create an aesthetic, and, whether for either necessity or pleasure, reshape the city’s landscape into a more productive and ecologically aware place.