The world’s biggest collection of non-nettly-looking nettles – or Urticaccae, for those in the know–as well native plants and flowers, are sprouting vertically up the exterior walls of The Athenaeum Hotel in London. The city’s humid microclimate is the perfect spot for the more exotic species. “It’s a fairytale dream of a wall,” the hotel website describes it, “erupting like a living tapestry with trailing tendrils and flowers eight stories high above Piccadilly’s red buses.”

Patrick Blanc’s Vertical Gardens are an artistic expression of his scientific practice. He’s spent decades examining the way numerous wild plants naturally grow on vertical rock faces and trees. As a result, he’s perfected a technique that enables urban plants to grow vertically without the need for soil. He employs a system of slats to secure artificial felt and myriads of strategically placed plant roots, with automated watering and fertilization. Botanical architecture.

For each location, he carefully selects plants according to local climatic conditions and the indented visual effect.

Since 1994, he has created over 140 public Vertical Gardens as well as many private installations. Those of particular note include:

The Quai Branly Museum in Paris

The Marithé & François Girbaud boutique in Manhattan

Herzog & De Meuron’s Caixa Forum in Madrid

The Aquarium in Genoa

The Siam Paragon Mall in Bangkok

The 21st Century of Art in Kanazawa, Japan