Growing African vegetables on buildings can save space and feed cities

As cities grow, more people need food. However, space for farming is limited in cities. Building facades can offer a solution for growing food. We asked landscape architect Karen Botes to tell us about her research – cultivating traditional African vegetables on walls.

What are ‘living wall systems’ and why did you study them?
Living wall systems are vertical growing platforms which usually form part of a building façade. Some are continuous, others modular.

Continuous systems are lightweight screens with pockets that can contain wet felted substrate layers, or rock wool, for the plants to grow in, or the plants’ exposed roots are kept wet with nutrient-rich fluids. An example of a continuous system is hydroponics.

Modular living wall systems are irrigated plant trays or pots containing soil and fixed onto a supporting structure on the building’s vertical surface. Modular systems are widely used because they make an immediate aesthetic