Sustainable Horticulture

New Environmental Technologies Demand Plants

Posted by sustainable_hort on January 24, 2010

This is an article I wrote about a year ago, but most of it still applies. Those of us that have worked in the plant industry are recognizing that, as the title says…”New Environmental Technologies Demand Plants.”

With both consumers and the nursery industry, 2009’s buzzword is still “green,” with “sustainability” close behind. This is a positive for the nursery industry in several ways.
In last year’s Nursery Book, we looked at how a “green” marketing opportunity was developing, and how some in the industry were responding. This trend only continues to expand as more companies and growers change their practices to match consumer demands.
But, an equally exciting are the new environmental “technologies” that depend, to varying degrees, on plants. Commonly, bioremediation uses wetland plants to clean water and soil. Now, smaller versions, or bioswales, are finding new uses in urban areas. First green roofs, and then newer vertical plant support products are creating a “green envelope” strategy where buildings are literally covered in a plant layer.
Environmental experts are recognizing that these “natural” technologies are actually less expensive than “hard” (concrete) alternatives. They can pay for themselves in reasonable timeframes and produce long-term savings. Even large corporations that deal in huge reclamation and developments have adopted these technologies because they work, and, more important, are cost effective.
“These are no longer just warm-fuzzy things we’d like to do,” said Paul Morris a landscape architect that works on planning and sustainable issues for Cherokee Investment Services, Inc., an international development firm. “There are calculable benefit costs that can now be identified.”
Innovative landscape firms have a tremendous opportunity to join this effort, position themselves as “green,” and dramatically increase their business.

“These are not little changes, but this is a sea change,” explained Morris, speaking at the annual meeting of Oregon Landscape Contractor Association in December. Industry studies predicted a $19 to 38 billion in the 2010 residential green building market, he said.
Morris said that his company has long recognized the many benefits of incorporating sustainable technologies into their projects.
In fact, his company, with $2 billion in assets, is the leading private investment firm in “brown field” development, working on abandoned and idle industrial and commercial urban sites often with environmental degradation and contamination, distinguished from “green fields,” undeveloped land outside urban areas. It plans to spend $250,000,000 on remediation projects, he said.

What Does It Mean to This Industry?
This trend is also capturing homeowners interest as they begin to add more green roofs, plant landscapes that handle the run-off from their home and driveways, build ponds and swales with their water-loving plants; or change impervious driveways to ones that absorb runoff and use tough, low-growing plant choices.
All these new environmental options require our plants, just maybe not the same ones we have sold for decades.
The most visible example of “plant technology” in the last few years has been the green roof movement. Both “extensive” or “intensive” green roofs have been used in Europe for decades, but have only recently developed a base of support in the US.
Most US projects are “extensive” roofs, those that are generally installed for environmental/ecological reasons, not as additional human living space. Storm water runoff control drives many of these extensive examples. But, numerous research projects have proven they reduce energy consumption and the urban heat island effect, improves air quality, and creates habitat for wildlife. As these benefits are more widely recognized, they will enhance the property values. A win all the way around.
In a recent Newsweek interview, architect William McDonough, who designed the Ford Motors complex near Dearborn, Michigan, pointed to the economic payback the 11 acre green roof provided. Calling it an “immensely practical exercise,” he said it saved Ford $35 million dollars, reducing costs from $48 million for concrete pipes and treatment plants, to only $13 million for a plant solution.
Eco-roofs that are visible from surrounding building may be irrigated, but often the roof is not watered. So, only tougher varieties that can go dormant for dry periods are chosen.
But, as consumers experience roof environments, there may be more demand for “intensive” designs that mimic regular landscapes. These designs move beyond the purely environmental uses to creating livable spaces…multi-use spaces defined and enclosed in almost traditional landscape plantings though many of the plants are at a smaller scale. Use of containers, raised beds, and deeper soils allow for larger and vertical varieties. This concept is more developed in Europe, though the re-urbanization movement with more concentrated condo living may demand more of these spaces be developed.
Yet, even within the more limited “extensive” options, the plant palette is still a work in progress. As Nigel Dunnett and Noel Kingsbury wrote in Planting Green Roofs and Living Walls:
“The horticultural potential of green roofs has yet to be fully realized. The majority of extensive green roof rely on a small number of species and cultivars that are use ubiquitously.”…”Widening the range of plant species used beyond the widely used sedum carpets has many potential benefits.”
But, one only has to look at the new California Academy of Sciences Building in Golden Gate Park, which is covered in undulating green roof. The project, which covers 4.5 acres, required 1.7 million plants! It is indicative of what this could mean to specific niche nurseries.

Nursery Owner Provides Early Knowledge
Ed Snodgrass, owner of Emory Knoll Farm, New Jersey, seems to be a pivotal figure in U. S. green roof development. His early interest in green roof plants meant he had to do the research, experiment with plants, and begin to develop useful plants. He did it and shared it in proceedings papers and a detailed book.
One of his earlier papers provided advise on plant selection criteria for extensive green roofs, including specific parameters for the plants. He stated they should be “low-growing, shallow-rooted, perennial plants that are heat, sun, wind, drought, salt, disease and insect tolerant …ecologically compatible, fast growing but not invasive, flame retardant and have low nutrition requirements. They should have shallow, fibrous roots, long life expectancy or be self-propagating, lightweight at maturity and have low maintenance requirements, Low-growing ground covers resist drying out and being blown over by wind. Evergreen plants and seasonally flowering plant make good combinations for providing aesthetical pleasing extensive green roofs year-round.”
This still left a lot of room to look at many plants, but at the same time, did significantly limit the parameters.
He later used his extensive Emory Knoll Farm experience with green roofs to offers six main considerations. His first consideration was to separate plant usage into two categories: ground covers and accents. The second was, generally speaking, the most reliable kinds of green roof plants are hardy succulents, though he recognized some variability due to local climates. His third noted that there are not only significant overall regional climatic differences in the U.S., but also microclimates that can affect installations. Fourth, there is considerable market pressure to have regionally appropriate natives utilized in the installations. Fifth, he encouraged upfront maintenance as a worthwhile investment to ensure the long-term health of the green roof.
But finally, he admitted that “what constitutes a successful and viable green roof is only just being discovered.” Translation…a market with room to expand.

The Green Envelope
As mentioned earlier, the green roof concept is quickly expanding into a “green envelope,” where the entire building is covered in plants. Again, most the ideas are coming from Europe. Yet, in North America, companies such as ELT Easy Green™ Living Wall Systems, Brantford, Ontario, Canada, and Greenscreen®, Los Angeles, California, offer different support structures for vertical surfaces.
Dunnett and Kingsbury have several chapters in Planting Green Roofs and Living Walls that describe the vertical façade systems now is use. They note that in projects “in central Europe, mostly (use) plants species native to North America and eastern Asia.
Yet, the authors state, “there is a need for more adventurous plant selection.” They feel it would help is those specifying the plants had a wider selection of sizes within a particular plant group. So, again, it could be a new market for growers.

Wetlands Technologies
Similar to the green roof movement is the increasing use of plants to control storm runoff and to clean water from various contaminated sources.
In storm water runoff, the traditional solution has been hard surfaces leading to drains that fed into a complex piping system, often combined with sewage. This has lead to various pollution and control problems, too many to discuss in detail here.
But, Portland, Oregon, is a prime example. The city is finishing the second “big pipe” (one on each side of the Willamette River) designed to carry the storm water to a treatment plant many miles away. But, during the planning and construction phase, the city started looking a both green roofs (see above) and “bioswales” to help control excess surface waters.
Bioswales are basically miniature wetlands. They also exist as “rain gardens,” where individual homes can landscape to hold and control water runoff. They capture water running from hard surfaces (streets, parking lots, etc.) and then slow and disperse it so that much of infiltrates into the soil. Capturing soil water both lessens the strain on the city’s drainage system and reduces later season watering needs.
Plants that thrive in bioswales and rain gardens are those that can survive both “wet feet” and long, dry periods. Clearly, just as with green roofs, this plant palette will need to regionalized to find those that match the climate and seasonal differences. Many natives are probably the first to be considered, followed by relatives from similar climatic conditions. It may be useful to remember that these bioswales are not in a natural setting, but an urban environment. All probable choices deserve at least a first look.
But, current choices include many sedges, reeds, cattails, bulrushes, and trees such as willows and poplars.
Similar to the green roof selections, this trend offers new opportunities for nurseries looking for new markets. A 2007 survey by the American Society of Landscape Architects confirmed this, listing drought-resistant, low-maintenance landscaping and vegetative stormwater management as major trends in 2008.

Rain Garden Promotion
As mentioned, bioswales can also, at a smaller size are becoming associated with homes and condominium situations. Again, they seem to represent a new approach to landscaping.
A network of nurseries in the Minneapolis/St. Paul area even created a program that supports this concept called “Blue Thumb – Planting for Clean Water™” It was originally developed by Rice Creek Watershed District, but drew industry attention. Professionals from local governmental units (watershed and conservation districts, cities, counties); nursery and landscape professionals; and non-profit and community organizations, all joined to support this Blue Thumb program.
Homeowners are encouraged to use native plant gardening, rain gardens, and shoreline stabilization in their home landscapes. Hopefully this will improve water quality by allowing partners to present a unified public education message.

Other Plant Strengths
This concept is obviously related to the topics of riparian protection, where plants have long been recognized for the ability to protect the soil from erosion, clean the surrounding runoff, and absorb CO2. The benefits are clear, and urban hybrids that can replace concrete and treatment plants will continue to expand.
Of course, many plants and especially trees are useful in sequestering CO2, and just planting more trees itself has a huge impact. Last year I wrote the benefits of more trees were so clear, the industry needed to build a marketing message around them. That is already happening with tree growers such as Bailey Nursery and J. Frank Schmidt & Son, Boring, Oregon.
But, why not take is a step further? Insist that municipalities, urban renewal products open space development use the more efficient varieties. Another direction for tree growers to study.

And Then…Science Fiction
Even food production is even moving up…literally. The Rocket Restaurant in Portland, Oregon, grows its herbs and greens on its roof. The system is primitive with crops grown in those small, inflatable swimming pools young children use in backyards, but it works.
This idea is even moving into almost science fiction, with multi-story structures, both enclosed and open, erected in urban centers, designed to grow food.
The most developed ideas come from Columbia University’s Dr. Dickson Despommier. His “skyscraper farm,” proposed for urban centers such as New York, was covered in the September 2008 issue of Popular Science. The article includes a detailed illustration of a 30-story, tube-shaped greenhouse skyscraper that Despommier estimates could feed 50,000 people. Using advanced hydroponics, robotics, and combinations of natural and controlled lighting; the structure produces a wide range of crops including a floor of chickens. It also uses the surrounding neighborhood’s sewage to provide both water and fertilizers for production. Obviously, the vertical farm’s technology is already similar to greenhouse production, and that segment would have a significant new market for its crops.
Though his design is focused on food production, it seems reasonable that several floors of this green tower might be used as pure, landscaped gardens for use by employees and the surrounding community. One more use for this unique concept.
Despommier is already working with Abu Dhabi and South Korea to build prototypes in for their new eco-cities. In the U.S., Seattle and Las Vegas are looking at similar concepts.
So, maybe as an industry, these new environmental activities and some of the wilder ideas can help reverse the last few years of slowing green industry sales. But, at a minimum, it will be an opportunity for the industry to also help solve at least several pressing environmental challenges.

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