Traditional and Rooftop Gardens1One might think of a typical garden as set in a plot of land, surrounded by plenty of sunny green space. However, the locations of modern gardens have expanded to include porches, balconies, and even rooftops. City dwellers do not allow their lack of green space to deter them from gardening. Although traditional and rooftop gardens offer similar benefits, they differ in many respects.2Traditional gardens are usually dug in the ground, but there is no soil on the tops of roofs. Rooftop gardeners have to be creative and careful when designing their gardens. One simple solution is to put plants in containers. Pots, milk crates, and wooden boxes work well, but they are also limiting. Some plants need more space to spread out than what a container allows. Over the years, people have tried putting layers of soil down on rooftops. The weight of the soil and the poor drainage led to leaky and unstable apartment ceilings. Today, gardeners know that waterproofing and supporting a roof, as well as designing a drainage system, can solve these problems.3Other differences between rooftop and traditional gardening are sun and wind. Both of these tend to be more extreme on rooftop gardens. After a good rain, rooftop gardens dry out quickly. The solution to this is mulching and watering. Trying to prevent the wind from blowing plants and soil is a little trickier. Other than building structures around their gardens, gardeners can do little to solve this problem.4Rooftop gardeners are faced with many challenges; however, they do have some advantages over traditional gardeners. In traditional gardens, gardeners have to contend with pests such as deer and rabbits. Rooftop gardens are safe from these pests. Another advantage to rooftop gardening is a longer growing season. In the spring, rooftops are drier than the ground and have warmer temperatures. This allows city gardeners to start gardening a few weeks earlier than gardeners in surrounding areas.Individuals are not the only urban dwellers who realize the gains from going green. City planners have jumped on the bandwagon as well. In recent years, several cities have begun promoting the installation of “green roofs,” which are roofs with plants on them to help promote energy efficiency. Rooftop gardens can keep buildings cooler, save energy, extend the useful life of the roof, and add beauty and useable space.6Chicago is one of the cities taking advantage of the benefits of green roofs. In 2001, a green roof was installed on Chicago’s City Hall. The project contributed to $5,000 in annual energy cost savings. It also improved air quality and reduced stormwater runoff. Today, Chicago has over 400 green roof projects in various stages of development.7People living in cities, suburbs, and rural areas recognize their own unique struggles with maintaining healthy and productive gardens. Although problems and solutions vary depending upon where a garden is, people everywhere reap benefits and enjoyment from their gardens

Question

Traditional and Rooftop Gardens1One might think of a typical garden as set in a plot of land, surrounded by plenty of sunny green space. However, the locations of modern gardens have expanded to include porches, balconies, and even rooftops. City dwellers do not allow their lack of green space to deter them from gardening. Although traditional and rooftop gardens offer similar benefits, they differ in many respects.2Traditional gardens are usually dug in the ground, but there is no soil on the tops of roofs. Rooftop gardeners have to be creative and careful when designing their gardens. One simple solution is to put plants in containers. Pots, milk crates, and wooden boxes work well, but they are also limiting. Some plants need more space to spread out than what a container allows. Over the years, people have tried putting layers of soil down on rooftops. The weight of the soil and the poor drainage led to leaky and unstable apartment ceilings. Today, gardeners know that waterproofing and supporting a roof, as well as designing a drainage system, can solve these problems.3Other differences between rooftop and traditional gardening are sun and wind. Both of these tend to be more extreme on rooftop gardens. After a good rain, rooftop gardens dry out quickly. The solution to this is mulching and watering. Trying to prevent the wind from blowing plants and soil is a little trickier. Other than building structures around their gardens, gardeners can do little to solve this problem.4Rooftop gardeners are faced with many challenges; however, they do have some advantages over traditional gardeners. In traditional gardens, gardeners have to contend with pests such as deer and rabbits. Rooftop gardens are safe from these pests. Another advantage to rooftop gardening is a longer growing season. In the spring, rooftops are drier than the ground and have warmer temperatures. This allows city gardeners to start gardening a few weeks earlier than gardeners in surrounding areas.Individuals are not the only urban dwellers who realize the gains from going green. City planners have jumped on the bandwagon as well. In recent years, several cities have begun promoting the installation of “green roofs,” which are roofs with plants on them to help promote energy efficiency. Rooftop gardens can keep buildings cooler, save energy, extend the useful life of the roof, and add beauty and useable space.6Chicago is one of the cities taking advantage of the benefits of green roofs. In 2001, a green roof was installed on Chicago’s City Hall. The project contributed to $5,000 in annual energy cost savings. It also improved air quality and reduced stormwater runoff. Today, Chicago has over 400 green roof projects in various stages of development.7People living in cities, suburbs, and rural areas recognize their own unique struggles with maintaining healthy and productive gardens. Although problems and solutions vary depending upon where a garden is, people everywhere reap benefits and enjoyment from their gardens

Which detail from the passage BEST supports the idea that green roofs can help cities decrease their power consumption?

A.
City planners all over the country are initiating the installation of green roofs.

B.
Over 400 green roof projects are being developed in Chicago.

C.
Rooftop gardens can improve air quality and reduce stormwater runoff.

D.
Energy costs at City Hall in Chicago decreased after a green roof was installed there.