Toulouse recently planted several of the trees and is following the lead set by Paris and Rosny-sous-Bois.
Each tree needs only a square metre of ground space and grows over a metallic structure, which can create a shadow of 45-50m² per tree.
They are made up of different plants, chosen according to the local climate of each location.
The tree is never higher than five metres and autonomous, each having a 200-litre water reserve, which is filled up two to three times a year.
French start-up Urban Canopee is behind the idea and began work on the project in 2016 with researchers from the École des Ponts ParisTech engineering school.
It won a prize at the C40 climate summit this year and is to present the project to 94 mayors in Copenhagen this month.
This year, 40 “corolles”, as the trees are called, have been ordered to be installed in France and other cities in Europe.
Co-founder Hubert Michaudet (pictured left with co-founder Elodie Grimoin) said: “We have had a lot of queries, even from Australia and the United States.”
The trees not only look good but also aim to fight against global warming by bringing more biodiversity and reducing air pollution.
Fellow co-founder Elodie Grimoin initially wanted to “reinvent the gardens of Babylon”.