In cities where space is a much desired commodity, vegetable gardens may be considered a luxury. But if you live in a building where a flat rooftop is accessible, you could create a great rooftop vegetable garden from container pots, trellises or even raised garden beds. Whether you have a small space or an entire building’s rooftop, here are a few ideas when planning your rooftop vegetable garden.
Image: Egan Snow (Flickr)
Container Veggies
If the garden is just for you and your family, using container pots is the easiest way to go on a rooftop. You can grow tomatoes, peppers and herbs in medium to large flower pots. Make sure to choose pots with holes drilled in the bottom for proper drainage. If you love tomatoes, you can actually buy a variety called Patio Hybrid tomatoes that were specially bred to grow in containers. Be sure to position your potted tomatoes away from strong winds, and make sure they get direct sun at least five hours a day.
Raised Garden Beds
If you have many more vegetables in mind or you are building your rooftop garden with a community in mind, building a raised garden bed may be the perfect option. You can make a container garden out of a number of things: metal washtubs, children’s plastic wading pools, wooden crates, used tires or even burlap feed sacks. The tub or planter should be able to hold enough water to feed the plant(s) adequately. If you are designing a large garden, make sure to leave a path between the container beds for foot traffic so you and your neighbors can tend to the garden.
Climbing Veggies
Some garden vegetables require space to climb. Cucumbers, squash and peas, for example, like to attach themselves to vertical things. A rooftop trellis is the perfect addition to your rooftop garden. If you simply want practicality, you can make a makeshift trellis from an old step latter or wire fence. Of course, you can always buy a more ornamental trellis from a garden store if you want the kind of garden meant for parties and entertaining.
Water Access
Before you think about planning a rooftop garden, you must consider water access. Does your building have a water faucet on the roof where you can easily attach a hose? If you are handy, you can provide your own water spigot with PVC tubing run from an indoor spigot and fitted with a closure valve. If not, plan on dragging pitchers of water up to the roof so you can properly water your plants. If you plan on being away for a few days, you can set your container plants in a water tray. The soil draws the water upwards from the drainage holes in the bottom of the containers. You may also consider green irrigation systems (collecting rain water in barrels).
Proper Drainage
Rooftop gardens cut down on rainwater drainage because the soil absorbs the rain and filters it while the plants put water back into the air. However, when you water your plants with a hose, you need to think about where the excess water will drain out and the structure of your rooftop. Rooftop gardens require an insulation layer and a waterproof barrier on which the soil can rest. You should also make sure that there is a root barrier that prevents plant roots from penetrating the waterproof layer. The garden should include a layer of clay, gravel, or plastic which allows water to drain.
Rooftop gardens have many benefits. Despite the obvious aesthetic benefits and gardening pleasure, a rooftop garden can lower temperatures. During the heat of summer, plants use evapotranspiration to transfer heat and moisture from the soil into humidity – making the air cooler. During the cold months, rooftop gardens serve as insulation, protecting buildings from heat loss and saving people money on their heating bills. Rooftop gardens collect the rain fall, as well as leaves and sediment, purifying the water before it enters the city’s sewer system.
Rooftop gardens are a great way to bring the community together too. If your apartment building does not already have a rooftop garden, check with your manager or landlord to see if they would be open to letting you plan and organize one.
April Lentini writes for Apartment Guide in San Jose
