WRITING: “Interview with Patrick Blank”
An interview with famed green wall designer Patrick Blank from 2008, published in Landscape Architecture Australia, Issue 118
Few landscape architects who work with architects would not have been asked in recent years “Can you do us a green wall?” The idea is so popular it has become truncated from noun to verb: “can we green wall that?” Yet despite their popularity, few green walls have yet been built in Australia, and correspondingly such confidence in this technology could be described as speculative to say the least. One person who has had a lot of experience with green walls or “Mur Vegatal, as he calls them in his native French is botanist Patrick Blank, who came to Australia last year to speak at the Landscape Australia conference in Melbourne. Blank has built at least one green wall in Australia in the Qantas lounge in Sydney Airport, and during the conference I had the opportunity to see his two generous lectures and interview Patrick, between meetings where he was courted by architects.
Blank is first and foremost a botanist. Both his lectures started from his own research into botany, particularly into tropical epiphytes, and were saturated with green-on-green photographs of luscious, moist surfaces and details of plant adaptations. The first lecture was focused his green walls tracking them from disturbing naturalistic, rotting installations in his bathroom to his recent painterly and compositional planting designs in Portugal. This lecture was generous because he freely described how he built these walls, including detailed information about weights and water usage, material performance, etc, delivered with an academic enthusiasm that was not protective of his intellectual property. In his book, that Blank roughly translated the title to me as “What it’s like to be a plant in the rainforest”, he investigated the structural bio-physical adaptations of how epiphytic plants hold themselves up, and so the second lecture Blanc gave was in many respects more instructive than the first. The botanical root, so to speak, is important to keep in mind when one considers any aspect of Blanks work, as is his own particular eccentricity. The green wall is an extension of this botanical thinking, and its mosaic ecological surface a manifestation of Blanks creativity. Despite few local examples of green walls, many criticize Blanks work as inappropriate to the Australian context, or being un-sustainable and both critiques may indeed be justified. However, in providing such a critique it must be remembered that Blanks own rationales are different: it is useful to think of Blanks work as propositional botany, as an odd science experiment, a creative extension of his science. His other rationales are a touch bizarre. Blank, who has green hair and wears green shoes, dismisses landscape architecture: “I don’t like it..”, he says, because it is “horizontal”. I question him further about this and he notes he is firmly an “urban guy”. He likes towns, the city, and he particularly likes cars, and believes that horizontal surfaces should be for people and cars not for vegetation, which, as one can imagine, should be vertical. Blank is earnest about this point and it pleasantly complicates what could seem to be a project that is about environmentalism, but which in fact isn’t. Blank is an urbanist and would ultimately like his system to cover all buildings.
When considering the mass deployment of green wall systems, designers should remember Blanks vision of such urbanism, because on consideration it reveals the biggest flaws in the idea. While occasional high profile buildings may be able to sustain a green wall, one need only consider faulty irrigation systems on accessible horizontal ground to see the potential problems. When an irrigation system fails on the ground there is still a buffer in the soil of some moisture that plants can live on. However if there is a failure in the green wall system there is no such buffer because the system in basically hydroponic. Consider further that if such a problem arose on a vertical, elevated surface it would have to be accessed with difficulty and considerable expense by specialists. Additionally such a surface would be covered by vegetation, and so the surface would have to be destroyed to discover the point of failure. While we may begin to develop more and more complex technologies to deal with these problems, the more complex the system becomes, the more maintenance problems would arise. After a certain point the green wall is no longer architecture or landscape architecture but industrial design or engineering. The potential maintenance issues for green walls require a paradigmatically different solution, and indeed one was proposed 20 years ago in Landscape Australia. In an article by Vladimir Sitta entitled “Living Epidermis of the City” Sitta proposed a solution that looked at the properties that building materials themselves might have, a way of viewing the problem not much different to Blanks research into epiphytes. Sitta extended ideas of materiality and patina so water storage could be achieved in the hydroscopic make up of the building material, like plants growing in cracks in sandstone, then breaking it up to create more plant growing media. This low tech approach works with the decomposition process of a fully functioning ecological community, something that has worked for Sitta in more recent projects too well. His film makers garden comprised a wall made of canvas sown with pockets and then irrigated, which accumulated seed and organic material, and then itself begun to rot. The project prospered but its owners started to become slightly worried by its viscous, fetid self-destruction, however in terms of a vertical, self generating ecology, it was an enormous success.
Visiting the Quai Branley recently, the notion of the green wall as an extension of ecology into the realms of painting is clear. In his lecture Blank showed planting plans that were decidedly Victorian, like perennial borders but vertical, and like them it is only when one visits them that their form becomes apparent rather than seeming blobily formless in plan. A layered design process is clear and comes from an understanding of microclimate rather than from any one floristic origin. Plants from numerous places are combined on the basis of their suitability to a microclimatic niche. Plants from the Amazon combined with plants from Asia look right because they LOOK like a spontaneous ecological system, with all the various vertical strata of the community represented. There is an economy of water here also because their layering allows for a plants transpiration to be caught by another plant. Looking at the face of the wall to the Seine, the surface is fully three dimensional and thriving even in winter, with many different types of plants from surface creepers to herbaceous and woody plants but surprisingly few ferns. Though there are pools of water on the ground showing how much water is needed to sustain this system (it is basically a waterfall), it works and has the exuberance that we would expect from it, though better surface grading at the base might allow more water to be caught than currently evaporates. It’s not inappropriate that a museum, a civic building, sucks a bit more water than other places might, however if in the Australian context we are interested in building shading perhaps judicious and patient tree planting might be a better, more sustainable solution.