Roof top gardening in the inner-city: Durban’s Priority Zone Rooftop Garden

Submitted by: Amanda Botes, Wednesday, May 9, 2012

Most companies that are based in the central business districts of South African cities have little space to have indigenous or food gardens on their premises.  However, thinking a bit more laterally (or vertically) reveals a multitude of unused space in inner-cities for this purpose. Many inner-city buildings, especially those from the modernist period, have flat roofs, which present opportunities for roof top gardens and green roofs.

The difference between rooftop gardens and green roofs

Rooftop gardens and green roofs are often used interchangeably but are quite different. Green roofs are roofs that are entirely covered in vegetation. The roof is planted with low growing, indigenous vegetation in shallow lightweight soil so that the entire roof can be covered. The main reasons for planting a green roof are for insulation, energy efficiency and to attract biodiversity. A rooftop garden does not cover the entire roof with vegetation and only has plants on part of the roof. The rooftop garden is more decorative and requires deeper soils so that higher growing plants and vegetables can be grown. Rooftop gardens often include outdoor living spaces for recreation.  The choice to grow a rooftop garden or green roof will depend on the benefits that a company is seeking from the initiative. This article will focus on an example of a rooftop garden in Durban.

The Priority Zone rooftop garden

A good example of a rooftop garden can be found at the Priority Zone offices in the Durban inner city on Monty Naicker Road. The roof of this one storey building has been transformed from an unused space into a lush garden that contains a variety of indigenous plants, vegetables and herbs and a well-used recreational space.  The rooftop garden is an initiative by the eThekwini Municipality’s Architecture Department and Drake and Scull, a facilities management company that uses the building. The garden was developed to serve as an example to other companies that it is possible to have a garden in the inner-city environment with limited space and that buildings can be retrofitted to be more sustainable. Below we highlight some of the key features of this magnificent garden:

Materials: In an attempt to be as kind to the environment as possible every effort was made to use recycled and reused items at the Priority Zone rooftop garden. Used tyres and 44 gallon drums found in the inner-city serve as flower beds, and old pallets are now walkways. Benches and tables were produced from recycled plastic.

 

Succulents grown in used 44 gallon drums that have been cut in half on the Priority Zone Rooftop garden

Fresh produce: A variety of vegetables and herbs are grown on the Priority Zone rooftop in flowerbeds or in tunnels under greenhouse sheeting and shade cloth. All the produce is organic and no harmful chemicals are used.  Crops are rotated to ensure that the soil is kept fertile. A wormery provides nutrient rich compost for the plants. The produce is sold to local restaurants and food markets and a large portion is donated to charities. The money from the sold produce is used to maintain the garden. The Priority Zone Rooftop garden has also started to grow madumbi’s, a local traditional crop. Local crops should be considered as they are hardier crops and may adjust better to changes in climate.

Indigenous gardens and biodiversity: In addition to the food crops the Priority Zone Rooftop garden is host to a variety of indigenous plants that require less water and have helped to attract bees, butterflies and birds to the garden.

Water harvesting: Food crops rely on a good supply of water to survive and in this garden water is supplied from six rainwater tanks that collect runoff from the building itself and a neighbouring building.

A created space: The Priority Zone Rooftop Garden was designed not only for the production of food but serves as a space for meetings and staff lunch breaks. A new space has been created with benches, walkways and a chess board for socialising and relaxing which adds value to the building.

 

The Priority Zone Rooftop garden showing indigenous plants in the foreground, walkways, food crops and the recreational space.

A holistic approach: The Priority Zone Rooftop Garden is part of a wider initiative to make the Priority Zone building more sustainable. The roof also houses a solar PV unit which powers the buildings computers and back up lights, and a solar water geyser which supplies hot water for over 100 staff that shower daily on the premises.

Awareness: Katherine Byron from Drake and Scull stated that the Priority Zone Rooftop garden has received a lot of publicity and attention and has resulted in “bringing people back into the city”. The rooftop garden has also enabled Drake and Scull and the eThekwini Municipality to inform people about the Priority Zone project that they are working together on and has raised the profile of the project. During COP17 the Priority Zone rooftop garden was included as part of a walking tour of the city for COP17 delegates where many ideas were exchanged between international delegates.

The Priority Zone Rooftop garden stands as a demonstration of what can be done on the multitude of flat top roofs that exist in South African cities.  Katherine Byron’s advice for other businesses wanting to start their own rooftop gardens is to think out of the box, re-use materials for planting and make the most of what you have. Katherine maintained that a rooftop garden does not have to be as large as the Priority Zone Rooftop garden and “can be done on a smaller scale” and will also provide benefits.

Benefits of rooftop gardens and green roofs

  • Vegetation reduces the indoor ambient air temperature of the building.
  • Local indigenous plants help to bring biodiversity back into the city.
  • Food production. Produce can be sold, used in the company canteen, or donated to a charity.
  • Creates more recreational space for employees as well as space for corporate lunches
  • Reduced run-off- Green roofs help to reduce the amount of water that runs off buildings decreasing the impact on stormwater drains and decreasing the risk of floods in the city.

The Priority Zone Project

The Priority Zone Project is an initiative by the eThekwini Municipality’s Architecture Department managed by Drake and Scull Facilities Management to improve the conditions of the Durban inner-city. The project focuses on a specific public area within the Durban inner-city and offers an integrated approach to service provision. Three areas are primarily focused on: Security, Landscaping and Cleaning and Waste Management.  Streets, taxi ranks and landmarks are being cleaned up and refurbished, vegetables are being grown in flowerbeds that had previously not been maintained and security guards patrol the area to ensure that the public is safe when using public spaces in the zone. A helpdesk operates 24 hours a day where problems in the area can be reported.  This project has been a success and has encouraged more people to visit the inner-city and use its public spaces for recreation.

For more information on the Priority Zone Rooftop garden contact Katherine Byron on kathbyron@gmail.com

Amanda Botes