Roof gardening is a form of plant cultivation that is carried out on top of a house or the building’s roof. Terraces and balconies can also be utilized. Various types of gardening can be undertaken; flat floor gardening or flat bed, vertical gardening which makes use of walls by creeping plants and hanging pot gardening. Remember the hanging gardens of Babylon! Why Roof Gardening? As pressure on land continues to increase especially in urban centres, roof gardening becomes an option. Other reasons include enhancing architectural and decorative designs, temperature control, own fruit and vegetable supply, habitat for small insects, bees, butterflies, birds, and lizards, among others.
Roof gardening offers wonderful recreational opportunities, not only as a hobby and pastime but promotes personal activity and exercise while tending the garden. It not only promotes greener cities but allows effective waste and water recycling, thus effecting environmental conservation. Green plants help to capture excess carbon dioxide emitted by automobile and industry which causes global warming.
Consideration of the weight of the soil must be based on the strength of the building’s floor slab. If you plan to build your own house, let the architect and the engineer know that you would intend to practise roof gardening. Lighter soil types should be used, such as peat moss and soil rite. If these are unavailable, try a mixture of garden soil (50%) saw dust (30%) and sand pebbles (20%), Such a soil mixture is not only lightweight but also enhances water retention and root development
You do not want soggy conditions on your roof. To allow excess water to drain off, apply a layer of waterproof bitumen on the floor. During construction stage, waterproof cement should be used on the floor. However, you may place burnt bricks (2″x4″ inches) next, place a net lawn on top to keep soil on place. If the space is large, place pipes along several places that lead to the main drainage holes and ensure they are covered by the soil. Alternatively, lay corrugated sheets across the floor. Leave 3 inches in between some sections to allow excess water run off to the main drainage holes. You can also place compact hay along the edges of the walls to guide excess water around towards the drainage outlet, ensuring it is not blocked. You may also improvise with covers to keep off heavy rains from damaging your garden, as indeed hot sun.
Plants you can grow
Roof gardening can support vegetables such as spinach, kale, parsley and lettuce. Fruits such as tomatoes, passion and grapes can also be grown. An excellent idea would be to grow medicinal plants with which you can make green teas and raw juices; they can include fast growing wheat grass, barley grass, amaranthus and dandelion. Other herbs and spices can be grown – rosemary, sage, fennel lemon grass, coriander and onions.
You can use plastic bags or containers to grow aloe vera, flowers and other plants of your choice. To separate different plant types, place planks of wood which can allow you to walk along them as you water your garden.