Rooftop gardening is a fun and rewarding way to enjoy nature from atop your building. But there are a few things you need to consider before beginning your rooftop garden.
First, choose your plants based on your roof’s conditions. If your roof gets a lot of sun, choose heat-tolerant plants like tomatoes and strawberries; if your roof is windy, try low-to-the-ground shrubs or ground covers that tolerate high winds.
1. Know Your Roof’s Conditions
A roof garden is a great way to improve your home or commercial building’s aesthetic and provide you with a healthy, green space. It’s also a good place to spend time with friends and family.
But before you start planting, it’s important to know your roof’s conditions. First, you should consult a licensed structural engineer to ensure that your roof has the capacity to support a garden.
Next, check local building codes for restrictions on height and aesthetics. And be sure to get permission from your building owners if you’re renting or the management company or co-op board if you own.
If you’re planning on growing plants, choose seeds and soil that will thrive in your climate. Radishes and Little Gem lettuces are great for small spaces, while trellising tomato varieties, such as indeterminate, will yield a lot of fruit over a long season.
2. Know Your Plants’ Needs
The first step in planning your rooftop garden is to know your plants’ needs. Rooftops are harsher environments than ground-level gardens in spring, summer and fall, so make sure you choose plants that will withstand these conditions.
You’ll also want to know your plants’ watering habits. It’s best to stick to a regular schedule to ensure your plants get the right amount of moisture each time they need it.
In addition, rooftops tend to be hotter than other locations, so you’ll need to keep a close eye on your plants to ensure they don’t overheat. This means you’ll need to select heat-tolerant flowers and vegetables like peppers, eggplant and cucumbers.
You’ll also need to plan for winter, since rooftops are essentially little microclimates and can overwinter many types of perennials that wouldn’t be hardy at ground level. Check your local nursery and garden center to find out what will work in your climate. They should have good recommendations for hardy plants that grow well in containers and don’t require too much soil.
3. Know Your Roof’s Weight
If you are planning on growing a rooftop garden, it is important to know how much weight the roof can support. It is a good idea to have an architect, building expert, or contractor tell you this information before making any changes to the roof.
The weight of your roof should not exceed 30 pounds per square foot. This number is based on a combination of dead load (the weight of the roof itself) and live load (anything permanently installed on the roof).
You will also need to consider how much water the plants need and where you can store it. It is a good idea to have a rain barrel or other storage solution available, especially in summer.
4. Know Your Roof’s Access to Water
If you’re gardening on your roof, you’ll need access to water. Containers and raised beds can dry out quickly in windy weather, so it’s important to have a reliable rooftop water supply, such as a spigot or rain barrel.
In addition, you’ll need to water your plants daily during the hot summer months when they’re most in need of moisture. Using a drip irrigation system can help cut down on watering time.
Tree branches and leaves can also create problems for your roof, so it’s important to check them regularly. Keep them clear of your roof to reduce the risk of limbs falling during heavy storms and causing damage.
Having an accessible way to transport materials and tools up and down your roof is also crucial. Carrying soil, pots, and mature plants is heavy and may require a lift or stairs, so be sure to check your building’s accessibility before you start gardening on your roof.