They have varied from magnificent multi-storey affairs planted by Patrick Blanc (in particular the side of the Athenaeum Hotel in Piccadilly) to a collection of plastic pots nailed to a fence. I have even made a film on the subject with Joe and Cleve.
At Grand Designs Live last week there was a very good, densely planted wall of ferns and one set out in boxes so it looked like a series of framed pictures. They have been, and doubtless will be again, at Chelsea Flower Show and all points in between.
The question really is, are they a good idea? The answer, and this is the case for many of life’s larger questions, maybe. Or sometimes. They are brilliant if they work but they, like this blog and many other things, are almost entirely dependent on technology. Without the help of irrigation systems, timers and pumps they are completely useless as they will expire in double quick time. They may be fashionable and they may be a marvellous way of “greening our urban environment”* but they are not at all sustainable.
In any sense of the word at it is a word that has a lot of senses, not all of them totally sensible. If you get my drift.
A green roof, on the other hand, is a much more self supporting entity when built well and can carry on undisturbed and unmolested by human involvement. It will get a bit weedy but it will survive on rainwater and will hum with sound of buzzing insects on a warm day.
So, my point is, having roundly dissed the idea of green walls, that I have just installed one for a client. This is okay because we are both under no illusions at all and we realise that it will need maintenance. It looks marvellous occupying, as it does, a high empty wall in deep shade beneath an overhang of thick thatch. Beneath it are some raised beds and a low square pond both of which have been clad in lead – which looks darn sexy. It was installed as a sort of modular pocket arrangement by a company called Treebox. The plants are tough and resilient (Bergenias, Vinca, Polystichum, Lirope etc) and are trickled with water for about two minutes every twelve hours.
I like it.
* That phrase is in inverted commas because I would hate you to think that I would ever write anything so dreadful without either a gun to my head or my tongue shoved firmly into my cheek.