The Skillman Residence.
The house won a 2009 Green Building Award. Bay Area, California

A few years ago, I spent a couple of peaceable afternoons with a good friend atop her California roof, weeding the landscaped grasses of her sustainably-built home. When we started, the large roof was an overgrown lawn; when we finished, the sweeping lines of the grasses and succulents were restored to their usual beauty. We agreed that roof-weeding was a perfectly pleasant and productive way to pass the time among friends.

A nice example of a living wall – Hotel Modera, Portland, Oregon.
Photo: Mike Davis/The Oregonian

One thing I learned from this experience, however, is that living roofs and walls require maintenance in the same way that my garden and window boxes need tending. Left to their own devices, they do what most neglected gardens do: they either dry up, or become overgrown. And I’ve thought, for larger urban buildings, that this is an entirely new and unaccustomed area of building maintenance activity for most businesses.

I found an example that confirmed my suspicion, the living wall on a large home supply and hardware store in our area. This wall was installed around three years ago, and I remember driving by it and being impressed. Now it looks like this:

Desiccated vertical garden, Thoiry, France
Photo: PK Read

Living walls can now be purchased in prefabricated modules, and can be installed to encourage storm-water absorption, insect, bird and bee populations, and function to clean air and cool large buildings.

But they require water-tight insulation on the inner building wall side, and just as importantly, irrigation and regular care on the green side. Things we aren’t accustomed to doing on the outer walls of buildings. In construction parlance, ‘dry wall’ usually means a wall built of a prefabricated material (as opposed to wet plaster). Technically, this wall would qualify, even if it no longer fits the builder’s original intent.

It’s likely that this modular garden could be ‘replanted’ with new modules – for the time being, dozens of noisy birds and at least one beehive have taken up residence, so it still counts as a ‘living wall’, I guess.
Photo: PK Read

Just because the requirements of green, living walls bring new challenges, doesn’t mean we can’t learn to adapt.

I’m hoping this will be a new job description for large cities: Wanted: Building maintenance expert. Must be an experienced vertical gardener.