In cities across The United States, urbanites have found a creative way to “green” their cramped spaces: building rooftop gardens and landscapes. Practically, there are several benefits to building a green space high above the ground. On rooftops, sun is ample, soil conditions are well controlled, and deer can’t eat into your flowers and produce! A garden can also beautifying an otherwise nondescript roof. As more and more people and businesses explore the possibilities of rooftop gardening, previously dull city skylines are becoming flush with verdant color.
What is a Rooftop Garden?
Rooftop gardens are typically comprised mainly of container plants—plants grown in beds or pots above the ground. Many rooftop landscapes also contain hardscapes like patios, fire pits, lighting, etc. Some rooftop landscapes are built as an added outdoor living space for people and businesses who don’t have conventional yards. Other rooftop landscapes are used for more practical purposes. An increasing number of urban restaurants, for example, are utilizing rooftop gardens to grow fresh food.
Because rooftop gardens and landscapes are cultivated above ground, they require extensive planning. Details like the type and size of planting containers, soil, storage space, wiring for lighting and miscellaneous electric fixtures, and other resources must be prepared before the landscape can thrive. It follows that a rooftop garden requires a significant amount of planning. Here are some starting points to consider:
Rooftop Gardening: What to Consider
Gardening on rooftops is often an exercise in compact gardening. There’s simply not much space on your average urban rooftop, so finding storage and planting solutions can be difficult. Luckily, people have been pioneering the art of gardening in cramped spaces for a long time. Using stacked planting containers that can fit atop one another on shelves, raised beds, vine climbing walls, and seating that has built-in storage space can reduce clutter. Many rooftop gardens incorporate design elements that are multi-use.
Daily weather fluctuations can be more extreme on top of roofs. Sunlight on concrete can be dangerously hot, and a lack of tree coverage means there is often little shade or protection from rain storms. Windy days are also much windier twenty or forty feet (or more) above the ground. For these reasons, rooftop gardens often need to be fortified and delicately cared for. Simple fencing or some barrier shrubs can provide shelter from gusty winds. A tarp or lattice wall can provide some shade on hot days and cool down shade-tolerant plants. Regular waterings can help plants fight dehydration, which happens quickly when the sun is directly above them. Ultimately, sun-loving, weather-hardy plants that retain moisture well are probably better suited for a rooftop garden than more temperamental varieties.
Safety is vital when it comes to rooftop gardening. Every year, hundreds of people injure themselves working on roofs. If you plan on spending a lot of time gardening at great heights, make sure the structural integrity of your roof is sound—it should comfortably support you and the weight of anything you’re installing. Ideally, work with a partner so you can watch out for one another, and make sure you have explicit permission to garden where gardens don’t typically go. Many landlords (and some zoning ordinances) forbid gardening on roofs.
It can be hard lugging necessary garden resources like fertilizer, mulch, and water up onto a roof. For this reason, work out the logistics of how you’re going to maintain your rooftop garden before you jump into building it. Running a hose up the side of a house or apartment is not always an option. Some rooftop gardeners chose to build rain gardens into their landscape to maximize water conservation. This is an Eco-friendly way to reduce the need for outside water sources.