Vertical Gardens, living walls, bio walls, green walls, green facade, breathing walls / active living walls, vegetated walls, vertical landscaping, grow walls, & others are the different names given to different or similar ways of growing greenery vertically. Many people have tried defining this in different ways. One may define & categorize these as under though few will have different views.
Vertical gardens cover all of the methods of growing, covering vertical surfaces of a buildings, structures or any kind of walls by growing plants/climbers from ground or from the wall itself by using, planters, modules, pots, fabrics, or by mechanically holding growth mediums of any kind, using whatever way & holding plants firmly, with provision of irrigation & drain system. Therefore this is a very broad definition.
In Green Facades, climbing plants are grown on a wall where in plants attach themselves directly to the surface or are grown on some supporting structure. Here, plants are always rooted in soil or some other medium at the base of the wall. Such green covering takes years to grow fully. The impact of mortality of one plant has impact on very large area going brown. & such plants can not be replaced easily.
The rest of the categories of vertical gardens are mainly covered under different Green wall systems. Under Green Walls system, plants are actually grown vertically in a structure attached to a wall surface, held over or away from it & it is separated from the wall by a waterproof membrane if required. These are mainly divided in 3 types on the basis of growth medium it has.
Loose Growth Medium
Most of the systems available in India are loose media system. There are modules or like plastic crates, small pots OR sacs placed in crates or racks or pockets in the fabric. The most of the applicators, Except Valencia Greens certified, buy modules from the manufacturers & use their own soil mix. Excluding Valencia Greens made growth medium, one has to replenish the growth medium with organic materials very frequently. The organic inputs like Cocopeat, FYM & other materials used by such applicators, deplete very quickly & to maintain the physical properties in one has to replenish it after 6 months or more. Many times it is changed within 2 years. Valencia Greens has experimented & developed many growth medium recipes, for different climatic conditions & these do not get eroded as there are three fold controls which hold plants & growth mediums firmly in new ELT modules, with growth medium to stay in place for many more years to come. Now with new addition of hydrophilic substrates having longest life up to 15 - 20 years Valencia Greens has brought the most flexible hybrid living wall system wherein regular Valencia Greens living wall modules have pre-planted hydrophilic inserts. Valencia Greens Green curtain system can also be covered under this category.
The first successful commercial green wall system was created by using mat media. These were created by world known French Botanist Patrick Blank, using his proprietary product of fabric mat & the other system components he has. He is instrumental in making green walls successful as well as popular. However in India these kind of systems have not gone beyond experimentation due to varied & extreme climatic conditions. Due to this few people use pocket system using fabric as material for creating pocket. However in this systems growth medium plays major role and not the mat substrate.
Structural Media including . Hydrophilic Foam
Structural media are growth medium "blocks" that are not loose, nor mats, but incorporate the best features of both into a block that can be manufactured into various sizes, shapes and thicknesses. These media have the advantage that they do not break down for 10 to 15 years, can be made to have a higher or lower water holding capacity depending on the plant selection for the wall, can have their pH and EC's customized to suit the plants, and are easy to handle for maintenance and replacements. They are the most robust option for a living wall for both exterior applications and for interior applications. They are also the best choice in areas where high-winds, seismic activity or heights need to be addressed in the design. Structural media are superior to the other media for their longevity and high-level of performance in a variety of circumstances. Depending on the installation, they do tend to be more expensive to install, but lower cost to maintain (Reference: WikipediA)
Valencia Greens has come up with the latest technology of structural media of Hydrophilic Foam having just sufficient water to take care of roots in the best manner. The products, flexigreen living walls & flexiroof are the products for green wall & green roofs where this latest substrate product/technology is used
Someone can also divide green wall systems on the basis of containers or on the basis of systems used for holding growth mediums mechanically as under.
Considering the varied climatic conditions & the challenges, Valencia Greens strives to give right solutions available for each project. With continued experiments, research & development, now Valencia Greens has introduced sustainable solutions in each category.
Non Modular System
In india there are very few systems available in market today, which make use of fabrics & that can retain sufficient water in the varied & extreme climatic conditions of India . As mentioned already, the fabric base system requires moderate temperatures and high humidity.
Wooly pocket system is a system wherein breathable felt pockets can be hung on any vertical surface. Wooly pocket system & similar systems are also successful in highly humid & ambient temperature zone.