A super-green housing estate dubbed the “vertical forest” in Chengdu, capital of Sichuan Province in western China, has proven anything but enticing to owners of the site’s 826 residential units, who have reportedly chosen to not move in their new homes until something is done about the scourge of the bleeding insects that have taken over the complex.
According to Agence Presse-France, the development of the Qiyi City Forest Garden, completed in 2018, had sold all units by April of this year. Between the completion of the eight-tower complex and the occupancy phase, however, the vegetation-covered private balconies attached to each unit were so overgrown that a mosquito infestation of epic proportions occurred. And while the disease-carrying insects are likely to enjoy the deciduous atmosphere, the infestation has prevented all but ten reported families from settling in the development, according to state media.
As the AFP explained, like most towers that were covered in greenery, the vegetation in Qiyi City Forest Garden was not planted for a particularly aesthetic sweep. The plants, which consist of over 20 different species, have been specially selected for their noise-reducing and environmentally harmful properties. (Chengdu’s air quality is among the worst in China, although it is improving.) But it appears the plants were too bulky and quickly got out of hand, causing tenant-repellent insect infestation and some serious post-apocalyptic vibrations.
“With no tenants to look after them, the eight towers have been overrun with their own plants – and infested with mosquitoes,” wrote the AFP. “Plants have swallowed up some neglected balconies almost entirely, and branches hang over railings all over the towers, as the footage shot this month shows. Paper was taped over some windows that were still visible behind the overgrown plants. “
In 2015, Civil Engineering, the magazine of the American Society of Civil Engineers, examined a report published by the Council of Tall Buildings and Urban Habitat that examined the pros and cons of the trend of covering towers with extensive vegetation. Using Stefano Boeri Architetti’s Bosco Verticale in Milan as an example, the report found numerous environmental benefits and some disadvantages / challenges, although insect infestation never occurred. The potential of green towers as a microhabitat for birds, bats and insects is generally viewed as positive. But in the case of Qiyi City Forest Garden, it got too flawed, too quickly.
As Laura Gatti, an Italian agronomist, botanist and frequent contributor to Stefano Boeri Architetti, explained in a statement to AN, the situation in Chengdu, where there was obviously no garden strategy or long-term vision, was “predictable” and avoidable: “
“The creation of a vertical forest is a complex project in which we, as doctors with degrees in agricultural sciences, bring in knowledge of phytopathology, entomology and phytoiatrics. First, the success and safety of the project, even at the design stage, depends on in-depth studies of the biological identity of the host’s geographic area. Subsequently to the constant application of an integrated biological control strategy aimed at maintaining the correct balance between the populations of the parasites and their natural predators. The challenge is much more complicated in environments with reduced and unbalanced biodiversity. Situations like in China are predictable and avoidable, also through constant dialogue with the residents. “
Fortunately, the upcoming mosquito forecast for Chengdu looks encouraging, which could offer absent homeowners a safe window in development to tame their overgrown balconies and invest in economy-sized citronella candles.