While rooftop gardens are not a new phenomenon, they have become increasingly trendy as urban populations grow and city-dwellers seek ways to increase their living space and stay in touch with nature. Humans have an innate affinity for nature so much so that merely being around greenery has incredible mental health benefits in reducing stress and anxiety. Further, green roofs have environmental benefits in cooling ever-rising city temperatures. If you’re looking to start a rooftop garden, but aren’t sure where to start, follow these 5 steps to being an urban garden pro!
- Get permission. The first step to planting is making sure that you have permission to do so from your landlord or building manager. Some buildings may have height restrictions that prohibit any additions to a rooftop area, may not have safe and easy rooftop access, or may prohibit rooftop gardens for fire safety reasons. Also check to make sure you’ll be able to access the rooftop with your plants and materials – some buildings won’t allow soil or plants in elevators.
- Structural integrity. Once you get the go ahead from the landlord, you will also want to consult a structural engineer as soon as possible to ensure that your building is able to handle the extra weight of a rooftop garden plus the weight of people walking on the roof. You will want to continue to take weight into careful consideration and maintain a relationship with the engineer as you proceed in choosing planting containers and materials.
- City plantings. Rooftops are great options for planting in the city because they typically have some of the best light exposure, especially compared to small apartment windows that are shaded by other, taller buildings. However, rooftops also present some unique environmental challenges to plant growth. Given their height, they tend to be quite windy, so plan to include windbreaks such as lattices or trellises. Rooftops also are prone to overheating. Many rooftop surfaces trap heat or reflect sunlight, so you want to be sure to balance giving your plants enough light, but ensuring they don’t overheat. Include shade elements such as pergolas, awnings, or umbrellas (but be sure that your roof can bear the extra weight).
- Water and storage. You won’t be able to rely on rainwater alone, especially in hot summer months, and lugging a watering can up to the roof is a pain. Make sure you’ll be able to run a hose on the roof or use a rain barrel to store water. Gardening will also require other tools such as buckets, soil, fertilizer, shovels, etc. Think about how you want to store this equipment in a way that isn’t an eyesore and doesn’t add too much weight. You can build a small closet or shed or use a set of shelves or trunk. You will, however, want to ensure that materials are secure so they are not swept up by the wind, becoming hazards for those below.
- What to plant and how. Last but not least, is the actual planting! Think about what you want to get out of your rooftop garden. Do you want it to be a relaxing space to hang out? Do you want to grow your own herbs and vegetables? If you’re seeking an outdoor living space, you’ll definitely want to think about privacy. A city is densely packed and any taller or adjacent building will be able to see your roof. Plant hedges or run vines up a trellis barrier to obscure neighbors’ views. For other plants, you’ll want to use container gardens, such as pots or raised beds. As with all other aspects, you’ll need to consider weight when choosing these. While wooden beds are classic and aesthetically pleasing, you may want to opt for some fiberglass or plastic planters. You’ll also want to find lightweight potting soil. In terms of vegetables that grow well on rooftops, most lettuces and leafy greens (spinach, kale, chard, bok choy) and herbs will thrive. Cherry tomatoes, zucchini, bush beans, and snow peas will also grow well. Root vegetables tend to be less ideal for rooftops because the soil depth they require will add a lot of additional weight. Finally, you’ll want to make sure that the plants you choose can withstand the environment of your building. For example, if you know your roof is prone to overheating, you may want to stay away from chard or kale unless you have a shade solution.
Now that you know how to get started on your journey to the rooftop garden of your dreams it’s time to make it your own with the help of a professional! If this seems overwhelming, you can start small and add on as you go until your couple of beds turns into a completed outdoor living space or flourishing urban farm. Good luck, and happy growing!