I’ve just put up a revamped article on vertical hydroponics http://www.marklaurence.com/articles/vertical_hydroponics.html which I first published on the Biotecture website. I put it here because it’s relevant – even accounting for commercial bias – to the understanding of urban greening. Actually, it’s not biased; my trialling and efforts simply showed that hydroponics work better, are more resilient (discounting the felt-based hydroponic systems) and lower maintenance.
The Biotecture system uses rockwool, an expanded basalt rock, which is inert and very stable. Interestingly, I wouldn’t use it as a growing medium for food production (although this is its primary commercial use) because I think there are recycling/disposal problems with the material, at least when used on a small/home scale. So although I’ve trialled a lot of veg (50 varieties) and they’ve all grown successfully, I will be developing another system for veg production. The whole idea of vertical urban food to me is to nurture independence, not dependence on supplies of a product that the end user cannot manufacture or directly re-use. Having said that, I’ve got a baby-leaf salad wall growing right now (at Biotecture) for a show! Displaying possibilities is also important to capture imagination…
