3 Steps To Creating An Urban Rooftop Garden

28 December 2015
 Categories: , Articles


According to some estimates, nearly half of Americans garden every year. If you live in an urban area, you might think that you don't have the space you need to create your own garden. Fortunately, you probably have all the space you need though. Where, you might ask? It's right over your head.

Here's a quick guide to creating an urban rooftop garden:  

Making Space

The type of roof you have will determine what type of rooftop garden you should choose. Most rooftop gardens fall into three categories: Flat Boxed, Hanging, and Scaffolded.  

  • Flat Boxed—boxed rooftop garden are ideal for flat or gently pitched roofs. Most boxed garden systems are relatively shallow and narrow, which allows for more even weight distribution and makes it easier to access and to tend to your garden from all sides.
  • Hanging—hanging rooftop gardens are ideal for steeply-pitched roofs. These gardens extend off of your roof like oversized gutters. Hanging roof gardens require a ladder to access. They are also very long and narrow.
  • Scaffolded—scaffolded rooftop gardens are a hybridization of boxed and hanging gardens. A Scaffolded garden is a series of tiered boxes (think stair steps), which can be sloped to accommodate virtually any type of roof. These rooftop gardens are perfect to maximize space on smaller roofs.

Making Drainage

Drainage is important for both your roof and your garden. Moisture should be able to flow beneath whatever type of rooftop garden system you install. Additionally, moisture must be able to escape from your garden containers.

To achieve drainage for your roof, you will need to raise your garden containers with box pillars.

  • Box Pillars—your rooftop garden must be firmly secured to your roof. When you install the box pillars, you will raise your rooftop garden and secure it to your roof, it's important to space your garden boxes so that your box pillars can be fastened to a roof stud. Most roof studs are space between 16 and 24 inches. Thus, your box pillars should be spaced 16 to 24 inches apart. You can find you roof studs with stud finders.

To make sure that your garden containers can drain, you will need to line your containers with a thin layer of sandy-gravel.

  • Sandy-gravel—mixing equal parts gravel and sand creates a stable base for your garden containers to sit. Lining your garden containers with a one- to two-inch layer of this mixture also allows moisture to percolate and drain from your garden containers.

Making Shade

One problem rooftop gardens never seem to have is getting enough sun. Unfortunately, they can be exposed to too much sun. They are also exposed to wind and just about anything else Mother Nature can conjure up. Another important decision to make for your rooftop garden is a system to shade and protect them from the elements.

  • Lattices—wood or plastic lattices can be used to create shade for your rooftop garden. When considering a lattice system, it's important to look for something with a low profile and sturdy means for fastening them to your garden containers.
  • Mesh Screens—regardless of what type of rooftop container you choose or lattice you install, you should also utilize a garden screen. Garden screens are cheap, easy to cut for custom sizing, and protect your garden from insects and anything else that might harm your garden.

If you live in an urban area you might think that having your own garden isn't feasible. Fortunately, a rooftop garden system can help you become an urban gardener. For more information about the steps described above, you may want to consult a commercial roofing contractor in your area.