Can living wall systems solve urban food poverty?

The Eco Green Wall, a locally produced, low technology system of light weight inter locking blocks of recycled polystyrene aggregate and cement with seed trays for growth medium and plants. Picture: Karen Botes

The Eco Green Wall, a locally produced, low technology system of light weight inter locking blocks of recycled polystyrene aggregate and cement with seed trays for growth medium and plants. Picture: Karen Botes

Published Feb 21, 2024

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As cities expand and populations soar, the challenge of feeding urban communities sustainably becomes increasingly urgent.

Traditional agriculture struggles to keep pace with urban growth, prompting innovative solutions to cultivate food within city limits.

One such solution, explored by Professor Karen Botes, is the concept of "living wall systems", which harness vertical space on building facades to grow crops.

Botes shared her research with The Conversation which delved into the cultivating of traditional African vegetables on walls.

The Vicinity wall with hexagonal pots containing geotextile plant bags with the growth medium and plants at the Future Africa campus of the University of Pretoria. Picture: Karen Botes

Living wall systems, Botes explains, are vertical platforms integrated into building facades, serving as innovative spaces for plant cultivation. These systems come in two main types: continuous and modular.

The plant palette of the Playground market comprises low-maintenance, hardy, water-wise edible and aromatic herbs such as pelargonium, wild rosemary and wild mint. Picture: Karen Botes

Continuous systems consist of lightweight screens with pockets or substrates for plant growth, while modular systems comprise irrigated plant trays or pots fixed onto supporting structures.

The advantages of living walls extend beyond food production, encompassing biodiversity, cooling, air purification, and noise reduction.

By bringing food cultivation closer to urban dwellers, these systems mitigate environmental impact, reduce waste, and foster healthier dietary habits.

Botes’ research aims to harness these benefits by focusing on growing traditional African vegetables on vertical surfaces.

Botes’ six-month study in Pretoria, South Africa, compared the performance of traditional African vegetable crops in two types of living wall systems: the Vicinity wall and the Eco Green Wall.

Findings highlighted the potential for local food production and environmental sustainability through innovative cultivation methods.

While living wall systems offer promising solutions, they face obstacles such as high installation and maintenance costs, reliance on electricity and water, and technological complexity.

To enhance their efficiency and resilience, Botes emphasises the importance of adequate sun exposure, soil quality, irrigation systems, and plant selection.

For cities in sub-Saharan Africa, the feasibility of living wall systems lies in selecting suitable crops, optimising growing conditions, and maximising space utilisation.

Traditional African vegetables, with their nutritional value, climate resilience, and minimal water requirements, emerge as ideal candidates for vertical cultivation.

Botes’ research underscores the potential of living wall systems to revolutionise urban agriculture in African contexts.

Picture: Zen Chung / Pexels

By harnessing vertical space and cultivating traditional crops, these systems offer a sustainable solution to food security challenges while transforming urban environments for the better.

Innovative approaches like living wall systems represent a promising step towards building greener, more resilient cities where food production is integrated seamlessly into urban landscapes.

IOL Environment