By : Jane Marsh
The amount of arable land in Africa is quickly diminishing, contributing to food scarcity and adversely affecting people’s quality of life. Even if the soil was pH-balanced and nutrient-rich, the rate of urbanization is soaring, and those who live in cities have very limited access to space for crop production.
People could solve both problems at once with vertical farming, a sustainable emerging innovation that involves growing plants upward instead of outward. This seemingly small change could make a huge difference, improving everything from energy efficiency to climate mitigation.
The Rise of Vertical Gardens in Africa
Climate change, overgrazing and overfarming have led to land degradation across Africa. In Kenya, 63% of the arable land is acidic. Locals try to make do, but often struggle. Benson Wanjala is a farmer in western Kenya. A few decades ago, his 10-acre farm produced 200 bags of maize annually. Today, his yield is just 30 bags.
While promoting sustainable agricultural practices and mitigating the effects of climate change could prevent and even reverse land degradation, people are already experiencing food insecurity. They can’t wait decades for change. Upward gardening is a more immediate, practical solution.
The idea that farms must consist of large fields with evenly spaced rows of crops is outdated. As arable land diminishes, building up poses an increasingly promising alternative to building out, prompting the rise of vertical gardens.
A Closer Look at Africa’s Vertical Gardens
Tuscillah Maoto lives in a one-room rental in Kajiado County, Kenya, a location known for desert vegetation, sparse rainfall and a seasonal river. She started a vertical garden there. She fills 20-kilogram sacks, jerricans and old tires with soil, poking holes in the sides to ensure adequate drainage and air circulation.
The soil mainly comprises nutrient-rich, compostable kitchen scraps, enabling Maoto to grow onions, pumpkin leaves, amaranth and African nightshade. She prefers native plants because they require less maintenance.
During the rainy season, she harvests rainwater for irrigation. The nearby seasonal river provides adequate water during the dry season. She even reuses the water she uses for chores, as long as it isn’t soapy.
More hobby and smallholder farmers are turning to vertical gardening. When this practice started gaining traction, private companies installed vegetation on the walls and rooftops of campuses and apartment buildings. However, it is accessible enough that people can successfully grow produce independently.
Communities can succeed where individuals fail, helping those who know little about farming. In Nigeria, one neighborhood co-manages three vertical gardens to share the benefits. Their system promotes biodiversity and lowers temperatures.
How Vertical Gardening Benefits Africans
Africa consists of arid desert, semiarid steppe, humid subtropical and tropical savannah climates. Many regions experience high temperatures and erratic rainfall patterns. Cities are particularly hot because the high concentration of concrete, metal and glass triggers the heat island effect — urban areas have significantly higher temperatures than the surrounding land.
Vegetation walls provide shade and insulation, naturally cooling down buildings without fans, ventilation or air conditioning. This feature enhances energy efficiency, which is a game-changer for those living in areas with costly or unreliable electricity access.
Plants also act as natural air purifiers. They can reduce concentrations of air pollutants like sulfur dioxide by up to 47.8%, nitrogen oxides by 36.2% and particulate matter by 26.7%. Improving the air quality in metropolitan areas enhances locals’ well-being, incentivizing them to grow vertical farms.
Urban vegetation promotes biodiversity, even at small scales. It attracts birds, honeybees and butterflies, facilitating pollination and food security. The plants could even support climate regulation on a larger scale since they passively sequester carbon.
Vertical gardening saves space and resources, making urban horticulture more feasible. It could mitigate the effects of climate change, improve food security, dampen noise pollution, promote biodiversity and enhance community well-being.
Applying Verticality to African Farms
As vertical gardening becomes more widespread, people will develop proven planting, growing and irrigation methods. Soon, large-scale upward farming could become standard. Farmers will benefit from understanding best practices.
Not every plant is suited for a vertical farm. For instance, some tree species have invasive roots that could damage plumbing, causing irrigation issues. While farmers could technically control root growth by spreading copper sulfate or potassium hydroxide around pipelines to inhibit growth, trees don’t stack easily.
Shrubs and stout grasses are better. Trailing, climbing and creeping variations will require maintenance, but also work well. Native species have adapted to local temperature, humidity and rainfall levels, making them resilient to rot, pests and infections.
Using lime on acidic soil is an agricultural best practice. Calcitic limestone mainly consists of calcium carbonate, which helps reduce soil acidity and improve fertility. It can substantially increase crop productivity when applied at least three months before planting season. Its alkaline nature may even repel pests.
Wood ash is an excellent source of calcium carbonate. It is also rich in other plant nutrients like potassium. The healthier plants are, the more resilient they are to pests and disease. Luckily, it is relatively easy to get, making it a great alternative to chemical pesticides.
The Future of Urban Vegetation Walls
Africa is home to the world’s fastest-growing urban areas. According to the Africa Center for Strategic Studies, its cities are expanding by around 3.5% annually. The continent’s urban population will double from 2025 to 2050, rising from 700 million to 1.4 billion.
As more people move to metropolitan areas, the need for solutions like Maoto’s urban garden will grow. Ambitious property developers may promise to build huge biophilic buildings to support the growing population. As great as this may seem, people could lose one of their primary food sources if the project is scrapped or the business goes under.
The future of urban vegetation lies in community-led efforts. Farmers could streamline acceptance by demonstrating the practicality and benefits of farming vertically. Promoting this innovative practice could eventually reverse arable land degradation, enabling them to achieve greater yields with less space.
Starting a Vertical Garden With Little Space
Growing upward instead of outward requires minimal space. Even if someone only has 1 square foot of floor space free, they could create a 6-foot-tall tower, enabling them to feed their entire family. Vertical gardening may not be the be-all and end-all of agriculture, but it is just creative and accessible enough to work.
Jane is an agriculture and environmental journalist and the founder and editor-in-chief of Environment.co, where she covers sustainability and eco-friendly living.
