Living walls in a domestic setting means climbers. In a commercial setting a hydroponic or soil container based system with built-in watering might make sense, but is way beyond the reach of the average gardener, so let’s stay real here.
Climbers are a great way to cover unsightly walls or other objects. Your main decision is whether to choose self-clinging climbers like ivy or climbers that require support like the climbing hydrangea.
Ivy is the climber everyone knows best. It is typical of this group, using hair-like structures on its stems to anchor itself to brickwork or concrete. Another self-clinging climber is Virginia Creeper (Parthenocissus quinquefolia).
Ivy quickly spreads up a wall without any help from you. It will also spread sideways and can become a weed. Variegated ivies are less vigorous and more interesting than plain dark-green ivy. All ivies are evergreen.
Virginia creeper is deciduous and is usually grown for its fiery red autumnal foliage. It comes into leaf in late spring and is starts to lose its leaves in early September. It is less weed-like than an ivy, though the long months with bare stems do not suit everyone.
Climbers That Need Support
My personal favourite is the climbing hydrangea (Hydrangea anomala (subspecies petiolaris)). This takes a few years to become established but then grows four feet a year. It is deciduous but comes into leaf early. The leaves are a bright green, complemented by large lace-cap type flowers that last for many weeks in semi-shaded position. Birds love to nest in this climber because it is in full leaf when they are nest building.
If you have a large inside wall to cover you could try growing a climbing hydrangea up it. It will not damage the wall because it is not self-clinging. You will need to provide sturdy support for this climber whether you grow it inside or out. Folding cedar trellis is not up to the job.
Honeysuckles are more scramblers than climbers. They look untidy when grown up a trellis, but are superb at scrambling over a wall, with or without additional support.
Fallopia baldschuanica, aka Russian Vine, aka mile-a-minute is a Must Avoid climber. It grows quickly enough to cover any wall in two years and then keeps on growing at 10 feet a year for ever. It has tendrils up to 150 feet long.