A wall full of plants might sound like a design trend, but in Latin America it has become something much bigger.

Spanish botanist Ignacio Solano says vertical gardens, first developed in Europe, have spread across Latin American cities on a far larger scale. “In Europe, it is normal for major capitals to have one, two or three significant vertical gardens,” he told Euronews Earth. “If you compare this with Buenos Aires, there are hundreds of vertical gardens there. Mexico City has hundreds. Guatemala City has hundreds.”

Since French botanist Patrick Blanc pioneered the concept in the 1980s, Europe has produced high-profile examples including Milan’s Bosco Verticale, a pair of residential skyscrapers whose terraces hold more than 21,000 trees and shrubs. The development converts nearly 20,000 kilograms of carbon annually and shelters 20 species of birds.

Research shows vertical gardens can significantly lower building surface temperatures, reduce heat absorption and improve thermal comfort in dense urban areas. Green walls also filter particulate matter, absorb carbon dioxide and provide habitat for birds and insects in places where space for traditional parks is limited.

Through his Alicante-based company Paisajismo Urbano, Solano says he is working to break down misconceptions about vertical garden technology while teaching others how to green their cities. He estimates he has helped install close to a million square metres of vertical gardens globally.

Solano is a biologist who has spent more than 14 years researching tropical ecosystems in places including the Chocó rainforest in Colombia and the islands of Madagascar and Réunion, studying how plants grow and interact in the wild.

He says choosing the right species for a vertical garden is essential and highly specialised. Altitude, climate and the position of the building all need to be considered, and plants must be grouped by adaptability and nutritional needs.

These gardens typically grow without soil and are fed by nutrient-rich water through a hydroponic system. “What we actually do is create a biofilter in the cities,” Solano said.

He said modern versions of the system now consume virtually no water and require just one maintenance visit per year. He also claimed the result produces three times more oxygen and grows three times faster than a conventional ground-level green space.

Solano’s company has spent more than two decades developing species selection methods and vertical garden technology, which it shares through its Guatemala City franchise, By Botanik. It has run intensive courses for students across the Americas covering botanical techniques, sales, contracts and species selection.

The courses are designed to be accessible. “You don’t have to be a botanist, an architect, or an engineer,” Solano said, adding that participants need enthusiasm and an appetite to learn.

Within five days, he says, participants can identify plant species by family, native origin and optimal placement on a wall. Of around 100 students in each cohort, he says 85 typically go on to develop real projects.

Read more from Euro News.