By Gabrielle Stannus
Thinking about getting into the green wall industry? Green office fit-outs and apartment living are both in vogue and demand for vertical gardens to fit these situations is increasing. Nurseries may benefit from this demand by growing plants for green walls and/or growing on planted modules or panels for green wall installers. If you want to get into this area, here are a few points to consider.
Green walls, also known as living walls, biowalls or vertical gardens, can be located indoors and outdoors. They can be installed to provide aesthetic and landscape design values, habitat provision, water purification, air filtering or other ecosystem services.
Green walls range from simple pot-based set-ups to more complex, fully-irrigated modular or panel systems. Modular systems are generally hydroponic or substrate based, whilst felt-based panel systems are usually hydroponic.
Junglefy is one business leading the way in green wall development in Australia. Junglefy are renowned for their work on the iconic One Central Park building, and more recently for their “Breathing Wall”, a modular green wall system designed to reduce indoor air pollution.
Andrew Wands, Junglefy’s Horticultural Manager, says that they have recently established their own production nursery to grow their own plants. Andrew still purchases plants and plant material from other growers all over Australia, including tissue culture plugs and Westringia, Lomandra and Nandina varieties.
Junglefy are expanding their plant range in order to keep up with demand. Like other green wall installers, Andrew continually searches for a greater variety of plants to put in these challenging landscapes.
Green wall plant selection should take into account climatic conditions on-site (light levels, wind exposure), maintenance requirements (more vigorous species require more regular pruning), aesthetic considerations, desired environmental outcomes and the type of system being used.
In Australia, epiphytes, lithophytes, hemicryptophytes, ferns, grasses, ornamental perennials and herbs are commonly grown in green walls. Green wall systems with a ‘fertigation’ (combined irrigation/fertilisation system) may favour smaller epiphytic and lithophytic species. Lithophytic species can grow in tiny pockets of soil on almost bare stone or rock, and epiphytic plants growing in similar niches on other plants.
Evergreen understorey foliage plants from tropical or subtropical areas are generally used in indoor green walls given their ability to tolerate shade and to respond to light when available, e.g. Philodendron scandens (Heart-leaf Philodendron). An outdoor green wall may include small trees and shrubs, depending on the scale of the installation, e.g. Metrosideros excelsa ‘Nana’.
If your nursery grows these types of plants, then perhaps it is time to spruik them to green wall installers, if you have not already. Or “tweak” plants to develop more aesthetically pleasing varieties that can perform well at even lower light levels, or more compact forms.
Planting out modules
Junglefy previously outsourced the growing of their green wall modules until their business reached a size where it became more cost-effective to do it themselves.
Your business may gain by forming a partnership with a green wall installer to produce their plants, and plant out their modules or panels. If you do so, ensure that your partner provides you with accurate, legible species list and planting plan so that your employees put the right plants in the right places. Good labelling of modules is critical here so you can cross-reference with the planting plan accurately. You may need to source plants from another nursery if the designer has specified stock you do not hold, so be mindful of plant availability before accepting the job.
Growing on modules
In addition to planting out modules, your business could also grow on modules for installers. Modules may end up indoors or outdoors, so your nursery may need a greenhouse, shade house and/or outdoor annex areas in order to propagate and acclimatise plants to the different sites they will end up in.
Production managers will need to factor in labour to weed, water and detail green wall panels, in addition to initial planting. When quoting on the job, make sure to allow for hold points in construction. Build clauses into your contracts to ensure that your business is paid if you have to maintain these modules for longer than expected.
One of the benefits of growing on green wall modules is that they can be stored vertically in your nursery, taking up less floor space. So you can theoretically fit in more plants per square metre. If planting in felt-based panels though, you will need to initially lay panels horizontally after planting to allow for better root establishment.
Explore the possibilities of selling off-the-shelf green wall systems, pre-planted or without plants, at your nursery. Make sure you plant up a demonstration to attract your customers’ attention.
And a great resource for Greenwalls, Roof & Facades - Growing Green Guide.