September 15 Presentation by Brian Hofmann, Feltrexx Intnl
The many uses, methods, and creative ideas for a Living Wall will be presented by Brian Hofmann, President, Feltrexx Internation of Modesto. With most clients being from the San Jose and San Francisco areas, Brian stated he and staff are delighted to share their knowledge and concepts on Thursday, September 15 at 12 noon in the Ceres Community Center, 2701 Fourth Street, Ceres. Open to the public, everyone is invited to this FREE lecture sponsored by the Ceres Garden Club.
Living walls or green walls are self sufficient vertical gardens that are attached to the interior or exterior of a building. They differ from green facades (ivy walls) in that the plants root in a structural support which is fastened to the wall itself. The plants receive water and nutrients from within the vertical support instead of from the ground.
Living or green walls have seen a recent surge in popularity. 80% have been constructed in or after 2009, and 93% date from no later than 2007. Many green walls have been constructed by institutions and in public places such as airports and are now becoming common to improve the aesthetics.
While the French botanist and artist Patrick Blanc is sometimes credited as having developed the concept in the late 1980s, the actual inventor is Stanley Hart White, a Professor of Landscape Architecture who patented a green wall system in 1938.
The system consists of a frame, waterproof panels, an automatic irrigation system, special materials, lights when needed and selective plants. The frame is built in front of a pre-existing wall and attached at various points. There is no damage to the building. Waterproof panels are mounted to the frame and provide structural support. There is a layer of space between the building and the panels which enables the building to breath. Green walls are low maintenance thanks to the automatic irrigation system, making them very water efficient compared to in ground gardens. Being hydroponic (soil less) makes them very clean and eliminates the possibility of soil borne pathogens. Green walls are most often constructed of modular panels that hold a growing medium and can be categorized according to the type of growth media used: loose media, mat media, and structural media.
Loose Media – tend to be ‘soil-on-a-shelf’ or ‘soil-in-a-bag’ type system. These systems require their media be replaced at least once a year on exterior walls, and approximately every two years on interior walls. They are not suited for areas with any seismic activity. Because the medium can easily be blown away by heavy wind and rain, they should not be over 8 feet high.
Mat Media – these systems tend to be coir fiber or felt mats. They are quite thin and can not support vibrant roots of mature plants for more that 3-5 years before the roots take over the mat and water can not wick through the mat. To repair, the mat must be cut out and replaced. These systems dry out quickly and often require a re-circulating water system and shallow root plants.
Sheet Media – semi-open cell polyurethane sheet media utilizing an egg create pattern has successfully been used in recent years for both outdoor and indoor systems. They do not break down for 10-15 years, can have a high or low water holding capacity depending upon the plant selection, and can have their ph and liquid nutrients customized to suit the plants, and are easily handled for maintenance and replacement.
Living walls are most often found in urban areas where the plants reduce overall temperatures of a building by addressing the problem of heat build-up – the absorption of solar radiation and the storage of this heat and its subsequent re-radiation, Plant surfaces, as a result of transpiration, do not rise more than 4-5 degrees above the ambient and are sometimes cooler, which reduces heat build-up resulting in a cooler building.
Living walls may also be a means for water reuse. The plants may purify slightly polluted water (greywater) by absorbing the dissolved nutrients. Bacteria mineralize the organic components to make them available to the plants.
For more information on the this topic and the activities of the Ceres Garden Club go to http://www.ceresgardenclub.org