There are many advantages of green roofs other than just looking good. They help to stop the rain gushing down and therefor stop storm water runoff as well as keeping the building cooler indoors. The benefit to humans and animals is that the plants process the carbon dioxide from vehicles and produce oxygen, without which we would not live. They retard fires and help to reduce both noise and air pollution. Once planted up, they will require watering or irrigation until such time as the plants have established themselves.
Spring flowering trees which a rich in nectar are Schotia brachypetala, Erythrina and Halleria lucida. Shrubs include Watsonias, Tecoma capensis, Aloes and Strelitzia regina.
Summer flowering plants include Burchellia bubalina, Kniphofia, and Agapanthus.
Autumn flowering Aloes like Aloe dyeri, Leonotis and Velthemia .
Winter has an abundant variety of Aloes, Salvia africana- lutea and Proteas.