Green Roofs - Living Architecture Monitor - Fall 2013 - (Page 19)

PLANT PROFILE SELECTING PLANTS FOR LIVING WALLS HOW TO DESIGN AND SELECT PLANTS FOR LIVING WALLS—AND A FEW GENERAL RECOMMENDATIONS BY: MARGUERITE WELLS T he plant palette for green walls is much wider than for most green roofs. The term “green walls” encompasses all forms of vegetated wall surfaces—green façades, living walls and retaining living walls. Living walls can be indoors or out, and made of soil, fabric or synthetics. They are nearly always irrigated, so drought tolerance is not particularly a constraint. In choosing plants for a living wall project, the parameters named above need to be outlined to give shape to the plant list. For indoor walls, tropical plants need to be used. Even with auxiliary lighting, the light levels indoors almost always necessitate plants that do not expect winter, which generally means tropical species. Outdoor walls can grow a wide range of plants, and the direction a wall faces is critical in determining the plant list. For example, a north-facing wall will sometimes never receive a single ray of direct sun. A south-facing wall may never have a moment of shade. East and west have different temperatures. Surrounding buildings affect these parameters as well. Winter care is a challenging part of wall maintenance. In the north, fabric-based, hydroponic walls are difficult to maintain perennial plants because the roots are exposed to the coldest outdoor temperatures, without the usual buffering effect that soil provides plants in winter. Even in soil-based walls, drying in winter is a problem—so look for plants that can withstand this. Winter aesthetic interest is also a factor—a wall looking green and beautiful in summer is not too hard to achieve, but keeping things looking even halfway decent in winter, and managing customer expectations regarding this, is a challenge in colder climates for exterior living walls. So, with all those parameters in play, how can I recommend any two particular species for living walls? One category is known as Mondo ABOVE: MONDO GRASS Image provided by: Melanie Cook Grass. Evergreen, tough and grass-like, I see this used commonly in outdoor living walls. Some cultivars are very popular, and as a result can be hard to get or expensive. Others are very common and relatively cheap. They are propagated mostly by divisions and are big plants that are not commonly found in small plug sizes because they just won’t fit. There are several genera of plants that use the common name Mondo Grass, including Dwarf and Black Mondo Grass, which are in the genus Ophiopogon, and the many cultivars of the genus Liriope, which come in mostly green foliage, including variegated green leaves, and many shades of blue and purple flowers. Some like more sun than others; some of the bigger varieties can be aggressive groundcovers. Some smaller selections are slower growers. Another common denizen need natives? sedum plugs or cuttings? mats, tiles or modules? READ THIS ISSUE ONLINE AT WWW.LIVINGARCHITECTUREMONITOR.COM motherplants LIVING ARCHITECTURE MONITOR / FALL 2013 / 19 http://WWW.MOTHERPLANTS.NET http://WWW.LIVINGARCHITECTUREMONITOR.COM

Table of Contents for the Digital Edition of Green Roofs - Living Architecture Monitor - Fall 2013

Green Roofs - Living Architecture Monitor - Fall 2013
Inside
From the Founder
Bookshelf – Eat Up: The Inside Scoop on Rooftop Agriculture
Green Roofs Boost Efficiency of Solar Panels
Grey to Green a Great Success
New & Upcoming GRHC Courses
On the Roof With… Industry Leaders
West Coast Green Innovation
Industry Research Collection
The Green Façade Inquiry
Creative Stormwater Landscaping
Leadership – Green Roof Leadership
Plant – Selecting Plants for Living Walls
Conference Agenda — CitiesAlive in San Francisco
Project – Green Walls for Greener Cities
Project – Living Architecture That Feeds
Project – Reduce, Reuse, Recycle
New Corporate Members
GRHC Buyers Guide
Hey EPA

Green Roofs - Living Architecture Monitor - Fall 2013