A botanist by training, Blanc studied plants growing on rock faces and tree trunks in the wild, finding that plants could do without soil and were happy to grow vertically as long as they had a steady supply of water and nutrients.

In the vertical wall of this London development, the plants are rooted into a layer of felt, laid onto PVC sheeting. This is stapled to a metal frame attached to the wall. Water and nutrients are delivered from the top, being distributed by capillary action to all the plants on the wall.

The design at Leamouth uses 160 different varieties of plant, from shrubs such as Berberis and Buddleja to Iris japonica and Corydalis, planted in drifts across the surface of the building. The planting was carried out by landcaping company Pantiles, following the design that was was simply spray painted onto the wall before planting. E-mail: info@pantiles-nurseries.co.uk www.pantiles-nurseries.co.uk

Apart from the natural attractiveness  of green walls, they also help keep to keep buildings cool in summer and warmer in the winter,  reducing energy consumption for air conditioning and heating. Green walls also reduce traffic noise, collect dust partuicles and absorn pollution.

A chapter on green walls can be found in a most entertaining book by Patrick Blanc entitled “Il bello di essere pianta”, Bollati Borighieri.  Original title “Le bonheur d’être plante”, Libella – Maren Sell Editions, Paris 2005. www.rhs.org.uk  www.bollatiboringhieri.it