A roof garden is a great choice for many people. For starters, it’s the perfect solution for would-be gardeners who don’t have a lot a space. Novice gardeners love the looks they can create using arrangements of containers. These gardens can create splotches of color in the midst of a drab urban environment. A roof garden can also benefit the environment.
What exactly is a roof garden?
It’s a garden you can grow on a number of roofs. Depending on your circumstances, you might choose your home, garage, an overhang or a shed. You can plant a flat bed or garden in terra cotta containers.
One of the best go-to sites for roof gardeners is TheEnvironmentSite.
What are the different kinds of roof gardens?
The three types of roof gardens get their names from the amount of maintenance, depth of soil and varieties of plants required.
Extensive living roofs need little maintenance and are a good fit for small extensions that don’t offer much structural support. The ideal plants for them are hardy and typically grow on cliffs or among rocks.
A strong underlying structure is a requirement for semi-extensive living roofs. Because of their deeper soil level, it’s possible to choose a greater number of plants to grow.
The largest gardens are intensive living roofs. These gardens require supporting structures that are both bigger and stronger than those found in most domestic buildings in order to grow a full array of plants and trees.
How does a roof garden benefit the environment?
There are a surprising number of benefits to the environment from roof gardening. Urban Roof Gardens provides details on the most important.
Green open spaces. Growing a roof garden creates green open spaces. To a degree, it offsets high-density development in urban areas.
Rainwater retention and management. A green roof can absorb up to 75 percent of a rainfall. This in turn significantly cuts runoff and the chances of flash floods.
Diverse habitats. A roof garden can become a habitat for native birds and insects, particularly when it contains indigenous flora.
Modification of urban micro-climates. Most cities contain pockets of urban heat because of huge amounts of concrete and asphalt. Due to transpiration, plants directly cool the air. During the hottest months, they can dramatically reduce the surface temperature of a roof.
Air quality improvement. As they remove carbon dioxide from the environment, plants add oxygen. Their leaf surfaces can also trap as much as 85 percent of particulates in the air.
Protection against heat and sound. Buildings with roof gardens lose 30 percent less heat in winter months than those without this type of garden do and are also cooler in the summer. Their plants provide protection against noise pollution in all seasons.
Economic advantages. Roof gardens can lengthen the lifespan of the existing roof fabric up to 70 percent. Residents realize additional savings from insulation benefits. Some gardens can significantly raise property resale values. If the garden contains fruits and vegetables for consumption, it can really lower the weekly grocery bill.
Places to socialize. Many gardens in the sky provide great settings in which neighbors can socialize. They encourage spending recreational time outdoors and foster an appreciation of horticulture.
Which types of plants will grow?
A roof gardener’s choice of plants varies according to the type of roof selected. However, mosses, lichens and sedum are popular due to their minimal requirements for nutrients and water. It’s easier to grow wildflowers in some roof gardens than in a traditional plot.
Vegetable gardeners report mixed results. The Kitchen reports that many gardeners say they have good results with herbs, lettuce, pole beans, snow peas, bush beans and bok choy. Other favorites are zucchini, cherry tomatoes, kale, mustard greens and spinach. Ornamental squash, chard and standard tomatoes, however, often don’t grow well in a roof garden.
Using containers is often easier and less expensive than constructing soil beds. Either type of roof garden benefits the environment, however.
Urban Roof Gardens site
The Kitchen site