Here are some more photos of our living walls we had on display at the Water Conservation Showcase. We have been experimenting with many species of native and edible plants in vertical applications. At our main office in Petaluma we have a 55 acre ranch and native plant nursery. The space and access to plants and nursery facilities enables us to create mock-ups and demonstration projects to test the new and innovative systems we are working with. Currently most living walls designed and built are using a pretty typical palette of plants that are extremely common and used throughout the country and the world. These plants include things like wandering jew, clivia, ivy, liriope, boston fern, philodendrons and flax. These plants are consider “no fail” options and designers are using the same palette regardless of location. At Design Ecology we use the natural systems specific to each project location as our guide in all our projects. Looking at “reference ecosystems” in nature we can determine how to design our built ecosystems. We have been studying naturally occurring living walls to try and determine some of the best native plants to use. We also use the characteristics of these native plants as a guide in finding other natives with similar characteristics that will be successful in vertical systems. I have included some images within these blogs of those natural systems I’m talking about.
We have had some very surprising results from tests in our nursery. Plants that we never thought would make it are doing great (like ceanothus) and other plants (like asarum) that we thought would be a sure bet, are not adapting. The walls are a hydroponic system (there is no soil). The growing media is an ultra-light weight foam. Water is applied through drip irrigation and so the system always remains a bit moist. But the constant wet conditions makes it a challenging environment for some CA native plants. That is why we were surprised at the happiness of the ceanothus, it’s a very drought tolerant plant that doesn’t need much water. Although we do think the constant water might shorten the life-span of the plant.
Through this experimentation we hope to compile a list of our own “no fail” natives, we already have some shoe ins! This will enable us to build walls that not only look amazing but also create small habitat islands for all types of birds, butterflies, native bees and more. We’re using some great habitat species, like the hummingbird sage and penstemon. We are also very excited about the potential for growing food. We’ve had success with a variety of perennial herbs and are looking forward to testing more edible plants in the system.
Lastly, the most common question I answered at the showcase, was “how is this living wall considered water conserving, doesn’t it actually use a lot of extra water?” Of course, I was ready for this question. Yes, the living wall needs water. But the hydroponic media acts a lot like a sponge, minimal water is applied and absorbed evenly throughout each modular panel. We dial in the irrigation system so that it only runs long enough to just soak each panel. Very little runoff, if any, actually occurs. It is much more water efficient that any of the other systems I have seen or experimented with.