Vertology Viridiwall Hydroponic Modular System
Green Walls have evolved over the last decade or so in two distinct factions; compost based and hydroponic, the latter meaning growing without a compost or soil medium. Green or living walls are distinct from green facades, which are generally climbers on a support frame or wire system. I have evolved several patented hydroponic living wall systems and worked with many other systems, in an install or repair capacity. My experience always leads me towards hydroponic rather than compost-based systems as these tend to provide better long-term conditions for the plants. Having said that, there still does not exist the perfect system and the health of a wall over time depends very much upon the maintenance and care given.
I am not a fan of felt-based hydroponics due to the inherent vulnerability due to the felt having little capacity to store moisture, so in the event of irrigation failure walls suffer very quickly. They also use 9-10 times more water than a mineral fibre based systems such as those available from my company Vertology Living Walls. All my conclusions are based on experience ( for example, I've previously installed an 800m sq. felt wall)!
Vertology Viriditrough Trailing Plant Hydroponic System
Hydroponic Living Wall Pros
Hydroponic Living Wall Cons
Compost Living Wall Pros
Compost Living Wall Cons