Patrick Blanc’s vertical garden at the Caixa Forum in Madrid is even more spectacular than the photos suggest. It is located in the old section of Madrid, beside the busy Paseo del Prado and near the Reina Sofia, one of Madrid’s outstanding art museums.
|Passers-by give a sense of scale.|
I wish I could give you some stats about this wall garden: how many plants there are, how high the wall is, how wide, but I can’t. I do know that it dates from 2007. And that the expanse of green was lush when I saw it a few days ago.
|Another view of the vertical garden shows the complexity of the colours and textures
and the three-dimensional effect of plants grown vertically.
The combination of plants creates a tapestry of colours and textures that stopped me in my tracks. (Stopped the non-garden types I’m travelling with, too.) On the wall I saw ferns, black mondo grass, sedum, fuchsias and many other plants too far above me to identify.
|An amazing variety of colours and textures create a living, three-dimensional tapestry.|
Many of the ferns and at least one of the grasses were changing colour, as you’d expect at this time of year. The hostas looked ready for a rest, but everything else looked in great condition. This is probably because of the watering regime: water and fertilizer applied automatically throughout the day.
|Black mondo grass, hostas and other plants|
Blanc explains his methodology like this:
On a load-bearing wall or structure is placed a metal frame that supports a PVCplate 10 millimetres (0.39 in) thick, on which are stapled two layers of polyamide felt each 3 millimetres (0.12 in) thick. These layers mimic cliff-growing mosses and support the roots of many plants. A network of pipes controlled by valves provides a nutrient solution containing dissolved minerals needed for plant growth. The felt is soaked by capillary action with this nutrient solution, which flows down the wall by gravity. The roots of the plants take up the nutrients they need, and excess water is collected at the bottom of the wall by a gutter, before being re-injected into the network of pipes: the system works in a closed circuit. Plants are chosen for their ability to grow on this type of environment and depending on available light.
Blanc says these green walls are good, sustainable installations that benefit the environment by insulating the buildings they are attached to and purifying the air around them. Others question this, suggesting that while Blanc has made a great contribution to the technology of green walls, the walls themselves use more energy than they save. I have no facts, so I won’t offer an opinion. I will say, though, that the walls contribute to the environment aesthetically.
The vertical garden is beside the Caixa Forum, a contemporary museum and art centre. The building combines old and new: solid and lacy steel panels sit atop a much older structure. I liked the contrast between the hard rusted orange and the soft and fuzzy greens; hints of autumn brown make a strong link between the two surfaces.
|The Caixa Forum and Patrick Blanc’s vertical garden form two sides of a courtyard.
The other sides are open to the street.
At a corner of the wall, just about at eye level where it is most vulnerable to pedestrians, I saw the underpinnings of the structure.
|The underpinnings are exposed at the corner of the garden.|
Standing close to the wall, this minor fault was easy to ignore. Looking straight up, I felt like I was at the bottom of a cliff where an unusually wide variety of plants had established themselves naturally.
|Looking straight up the wall.|
Blanc has installed another vertical garden in Madrid, inside the Torre de Cristal, a building designed by César Pelli and completed in 2008. With an exterior this extraordinarily lovely, I can only imagine the beauty of the garden inside.
|Crystal Tower, Madrid is in the foreground;
behind is a round tower designed by I.M. Pei.