花园屋顶有利于人与环境

Water is a necessity of life. Rain, especially, helps plants grow and stay green. But too much rain -- especially in cities -- can lead to flooding. That can cause waste water systems, like sewers, to overflow and send pollutants into rivers and other waterways. To fight the problem, several cities in the United States are starting programs like rooftop gardens.

A labor of love

A team at the University of the District of Columbia in the nation's capital has created a garden on the top of one school building. The garden holds many kinds of plants to help absorb rainwater... and grow food at the same time.

Architect David Bell has designed five "green roofs" for the university. He says he is excited about the project because "it meant doing something more than just dealing with storm water management."

"It took advantage of a resource above the city that you see all over where you have these flat roofs that aren't doing anything and it really made it something that was about urban agriculture."

Rainwater is collected in large containers and sent through a system that waters the rooftop garden.

The roof is filled with green life that appeals to insects.

Urban agriculture

In cities, "you don't have that many spaces to choose from and so rooftops are just (unused) space," says Caitlin Arlotta. She is a student in the school's Urban Agriculture program.

The project is part of a research program to see which plants do well on rooftops. The researchers are looking at plants including strawberries, tomatoes and sweet potatoes.

"We have the same experiment running with tomatoes as we do with strawberries, so we're doing variety trials and we're trying just to see which variety grows the best in a green roof setting."

Community involvement

The university also has other green spaces.

"We also have our own farm experiments," Arlotta said. "Within each of those growing systems, we want to be able to tell people which sorts of these crops grow the best."

One goal of the program is food justice; or in Arlotta's words, "bringing fresh food into cities where you wouldn't necessarily have that access."

And that includes produce that might be more recognizable to immigrant members of the community.

"In the U.S., it may not seem very common to use hibiscus leaves and sweet potato leaves as food, but in many places around the world it is."

Surprisingly productive

Sandy Farber Bandier helps run UDC's Master Gardener program. It seeks to improve cities and make them beautiful by training people to become Master Gardeners.

She says she's been surprised by the garden's output.

"My biggest surprise was that we produced 4,250 pounds of produce the first year and was able to disseminate that to people in need."

Spreading the wealth

She likes being able to show people who live in D.C. and others beyond the nation's capital what -- and how -- food can be grown on a rooftop.

"This is the future for food. What we have established here at this college is food hub concept of you grow it here, you prepare it in a commercial kitchen, you distribute through farmers markets, food trucks, and then you recycle."

I'm Susan Shand.

VOA's Julie Taboh reported this story. Susan Shand adapted this story for Learning English. Caty Weaver was the editor.

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