The orange trumpet vine hits a vibrant note in the chorus of colors on Manhattan's Lower East Side.
The Liz Christy Bowery Garden, with its peach trees and tomato vines, could be just another local lot where green has replaced gravel. In fact, it signifies how urban agriculture has blossomed in the past two decades in several forms.
From Seattle to Shanghai, people are growing food on rooftop gardens and in hydroponic solutions in stairwells. City farming now accounts for 15 percent of the world's food production, according to the United Nations Development Program (UNDP).
"Urban agriculture has been increasing very rapidly since 1975," says Jack Smith, director of the Urban Agriculture Network in Washington, D.C. "It varies according to culture, economy, and in some cases climate. But it is an important trend only now being really studied."
The trend has spread and broadened to include farms on the urban edge.
In 1970, 20 percent of families in Moscow were involved in some kind of agricultural activity, while today about 65 percent of Muscovites practice urban agriculture, according to UNDP.
For many, that can mean getting just beyond the city limits. Every year around the middle of May, Moscow's suburban train stations fill up on Saturday mornings with men and women bearing gardening tools and determined looks on their faces. Winter's snow has melted and "dacha season" has begun again.
If the word dacha conjures up log cabins in the forest, think again. Dachas - and most Russian city dwellers have one - are generally little more than an excuse for a surrounding vegetable plot. And those vegetable plots are central to Russian larders and psyches.
It has been estimated that individual gardeners, tending their tiny plots intensively during Russia's short growing season, produce as much as a quarter of all the country's fruit and vegetables. Potatoes by the ton, of course, and carrots and beets, but also cabbages and cucumbers to be salted and stored through the winter, damson plums and black currants to be conserved or made into jam, garlic and onions to be strung together in wreaths.
By the middle of September, as frost approaches, most of the harvest is safely in. And all over Moscow, in cramped apartments, a winter's worth of borsch is stored away wherever a mason jar will fit.
Farming on former dumps
In Kenya and Tanzania, 3 out of 5 families in towns and cities are farming. And in the United States, more than one-third of the dollar value of agricultural products is produced in urban regions.
Urban agriculture covers a broad range of activities and people. In Nairobi, Kenya, poor people farm on sites where garbage has been dumped and burned because the soil there is richer. They raise beans and corn to eat and sell.
In Zambia, some middle-class families earn a second income by growing and selling potted houseplants.
Urban farming includes more than growing crops on land that lies between buildings or near airports. Fish and other water life can be raised and harvested in tanks, ponds, and rivers. Rabbits, guinea pigs, and chickens are raised in bookshelf cages hung on walls. At last count, Cairo had 80,000 head of livestock in the city, according to UNDP.
Or take Dar es Salaam, Tanzania. Between 1968 and 1992, the number of urban farmers grew from 18 percent to 68 percent. Today, 90 percent of leafy green vegetables sold in the city's markets are grown in the city. Tanzania lacks good roads and refrigerator trucks, meaning there is no reliable way to receive food from rural areas, Mr. Smith says.
"The poor spend nearly 90 percent of their income on food. So there's no way they can make enough to buy all their food," Smith says. "They have to grow it."
In the US, where most people don't need to grow their own food, urban agriculture is still sprouting fast. The interest reflects a shift away from the monolithic food-delivery system that grows, harvests and delivers produce to a supermarket, Smith says.
In fact, urban gardening isn't necessarily driven by need. France's agricultural bounty has made urban farming "extremely limited," says Victor Simeon of the Paris-based Permanent Assembly of Agriculture Associations.
Old city structures, with their limited space, mean that urban gardens are usually limited to a colorful profusion of geraniums on the balcony. And since French farmers vend fish, meats, fruit, vegetables, and dairy products at city markets, Mr. Simeon says, there's little need to cultivate a city plot: Urbanites have constant access to fresh, inexpensive produce without getting their hands dirty.
But an urban agriculture of sorts is developing, if only by default. "As cities advance ... we're left with islands of agricultural land in urban settings," says Francois DuPaty, of the Isle of France Chamber of Agriculture.
These farms, which occupy 7.5 million acres of land, yield 12 percent of the country's agricultural output, according to the Ministry of Agriculture. As that percentage is expected to grow, farming groups are studying how cities and farms can coexist, particularly in the crowded northeast. One benefit they've already acknowledged: Farming in urban areas makes getting the goods to market that much easier.
In Germany, tough regulations have accounted for the preservation of farmland that, given its proximity to cities, would likely have given way to shopping centers in the US. Aboard a streetcar between Bonn and Cologne, a rider can still pass through cabbage fields.
But city farming isn't immune from criticism. Some experts say fertilizers, pesticides, and auto exhaust can contaminate plants. Because the lack of transportation costs means lower prices, others point out, city growers can rob rural farmers of their livelihood.
But fertilizer runoff can be a problem in the country, as well, says Jonas Rabinovitch, an urban planner for UNDP. In addition, urban agriculture is sometimes viewed as a marginal activity.
'The creativity is amazing'
But studies have shown urban agriculture to be central to millions of people around the world.
In Kampala, Uganda, about 70 percent of the population's need for meat and eggs is met by farm plots inside the city.
In Hong Kong, vegetables sufficient to meet 45 percent of local demand are produced on 5 to 6 percent of the total land area.
"The creativity is amazing," Mr. Rabinovitch says. "In Mexico there is a system of raising cactus plants in boxes.... People show a tremendous ability to do a lot with a little space."
Yet for all the new attention on this phenomenon, it actually traces back to the earliest of cities. The Aztecs, Mayans, and Incas all farmed within their settlements. Early maps of Germany and Paris show how urban agriculture was a part of the cityscape.
City gardens aren't just another place for upscale urbanites to get a little soil under their toes on the weekends.
The Green Oasis, a garden on the lower East Side of Manhattan, has become a home to more than 40 species of trees. It also provides the neighborhood children with a chance to work and learn.
"We have one of the highest rates of tuberculosis, AIDS, and single mothers," says Green Oasis gardener John Tesch. "Our outreach gives them some stability and a chance to see where their vegetables come from."
Urban agriculture also helps develop sustainable food systems. Just Food, founded in 1995, provide farmers in the New York City area with outlets for produce sales while increasing the availability of nutritious, locally grown food to low-income and homeless people.
"Many soup kitchens are overwhelmed. We can teach people how to grow food," says Phil Tietz, program director for the Green Guerrillas, a 25-year-old nonprofit group in New York, and a board member of Just Food. "Rooftop gardens are a big potential that haven't even been scratched yet."
But questions of land ownership can be a problem. This past spring 25 gardens in New York were razed to make way for low- and moderate-income housing. In Thailand, the government has done little to encourage urban farming and permits to farm are hard to get, according to UNDP.
Other countries, however, have well established policies.
Since Russia pulled out of Cuba in 1989, city farming in Cuba has taken off, says Urban Agriculture Network's Smith. The government sponsors two television shows a week on farming techniques, a national women's organizations supplies people with land, every neighborhood has a seed store, and farmers' markets abound.
Most gardeners don't see their work as fitting into the theme of sustainable development that tops so many UN conferences these days.
"These gardens are sites for food, flowers, or herbs; for marriages, bar mitzvahs, and plays," says Peter Mann, an avid city gardener and member of World Hunger Year in New York City. "They become very important spaces in many low-income areas."
* Staff writers Peter Ford in Moscow, Nicole Gaouette in Paris, and Ruth Walker in Bonn, Germany, contributed to this report.