Cities all over the world are turning green as people plant gardens on the roofs of towering buildings. These green roofs provide plenty of benefits to the people who grow them and to their neighbours, so it’s easy to see why their popularity is surging. They’re also fairly easy to construct. Anyone who is willing to put in a little bit of effort can start one of their own.
What are They?
A green roof is more than a garden on the top of a building. The green roof starts with a conventional roof that acts as the base. Several layers of support and insulation are placed on top of it, and a sturdy layer that protects the roof from water and roots goes on top of those. That layer of protection is followed by a filtration and drainage system. A growth medium goes on top of that, which allows the plants to safely grow on the roof.
What are the Benefits?
Green roofs offer plenty of benefits to the aspiring gardener. Their most obvious benefit is their potential as a food source. Malnutrition is a serious problem, even in developed nations, and green roofs offer a chance to produce food in the middle of cities. Many cities also suffer from food deserts, where people who cannot travel long distances don’t have any opportunities to buy fresh and healthy food. Green roofs reduce the need for transportation and long trips to stores, significantly improving nutrition in urban areas.
They can also improve the environmental conditions in urban areas. Cities tend to retain much more heat than rural areas, and can be several degrees hotter than the surrounding region. This is called the heat island effect, and it’s more significant than it first appears. A difference of even a few degrees can disrupt local weather patterns and increase the probability of medical problems from heat exposure. Plants absorb light and use it to fuel photosynthesis instead of retaining it, so they can do a lot to fight against this effect. Plants also act as natural air filters and can reduce the air pollution that inevitably occurs when hundreds of cars and homes are packed into a small city.
It’s also important not to overlook the visual impact of a green roof. Most people like to see some greenery in their daily life, and it’s often lacking in cities. Green roofs are a powerful tool for beautification, and they can help set the tone for a neighborhood. People are less willing to litter in an area that seems clean or to vandalize a pristine location, so they can prevent eyesores from developing.
Growing on the Roof
Building a green roof isn’t hard, but it does take planning. The first stage is deciding which plants to grow since that informs every other decision. Grass is the easiest option, and it provides all of the benefits of a green roof except for food production.
People who want to grow food need to do a little more work to pick the right plants. The plants need to be small and relatively light to avoid putting too much strain on the roof. They also need to have fairly shallow roots, since there isn’t much space to grow down. It’s best to avoid plants that need too much care if the roof is hard to access, but that’s not a concern for every roof. Leafy green vegetables, like lettuce and spinach, meet all of those requirements. They grow fast, they produce a lot of food, and they don’t need much care. They’re the ideal plant for a green roof, and most beginners should start with them.
Research the chosen plants and pick soil that can support them. Every plant is different, but most of them can handle topsoil from a store. After the roof is finished, be sure to track the amount of rain that falls on it. Too much water can kill a plant, so it’s best not to water them if the rain is taking care of it. However, there are times when they’ll need extra. The plants will thrive as long as they are suited to the local environment and get water when they need it. They will provide their owner with plenty of food in return.
