The report is the result of a survey of native plant material users from across the entire Eastern United States, with 760 respondents, and includes written comments. The respondents are drawn from NGOs, government, and commercial entities involved in ecological restoration projects and native plant production.
Amidst gradual reopening in parts on the world, the COVID-19 pandemic continues to affect nearly every aspect of life, from personal interactions to business to learning to recreation. The American Society of Landscape Architects (ASLA) is sharing insights, observations, and impressions from ASLA members based around the country here on The Field. In recent weeks, we’ve shared updates and resources curated by the Community Design, Historic Preservation, and Children’s Outdoor Environments Professional Practice Networks’ leadership teams. Today, we share dispatches from the Planting Design PPN team:
Mark Dennis, ASLA – Washington, D.C.
Anne Spafford, ASLA, MLA – Raleigh, North Carolina
David Hopman, ASLA, PLA – Arlington, Texas
Mark Dennis, ASLA
Senior Landscape Architect, Knot Design
Like all work-at-home, school-at-home, everything-at-home families these days, our own needs for outdoor connections are more persistent and unyielding than ever. We are here in Capitol Hill just a few doors down from Lincoln Park, a key element of the L’Enfant plan and among the oldest parks in Washington. The surging activity at Lincoln Park during the pandemic provides proof of just how crucial even the most fundamental aspects of amenity planning are in our society, while simultaneously highlighting the profound, persistent lack of funding for preservation and maintenance.
One of the best parts of my morning routine is to take a brisk-paced walk with my wife through our leafy suburban neighborhood in Arlington, Texas. It is a great chance to catch up on events, enjoy the changeable weather patterns in North Texas, greet and (occasionally) get caught up with our neighbors, enjoy the mature vegetation, and get the blood moving before a busy day. The neighborhood has very low non-arterial traffic flow that allows people and cars to comfortably coexist on the asphalt streets that are without sidewalks. However, at several points along our route, it invariably happens—the rise of the machines! Our morning reverie is interrupted with deafening sounds and billows of pollution and dust from gasoline-powered lawn and garden equipment (GPLGE).
These “machines in the garden” are ever with us, as was recently confirmed by a visit to Bloedel Reserve on Bainbridge Island near Seattle. Bloedel is one of my favorite places to return to and I always take the opportunity when I am in Seattle. Unfortunately, my aesthetic reverie at Bloedel was impacted by power equipment during my visit this summer and then became one of the incitements for this post.
As landscape architects, we are often responsible for designing the landscapes that are maintained by these environmentally and aesthetically abusive machines. Many people have written over the years about lower-maintenance alternatives to lawns and hedges, but adoption has been painfully slow. There is also surprisingly little emphasis on the effects of GPLGE on environmental quality by ASLA and by regulators. In Texas, the primary regulator for emissions is The Texas Commission on Environmental Quality (TCEQ). Their website has many suggestions for improving air and water quality. Drilling down to Voluntary Tips for Citizens and Businesses to improve air quality will eventually lead to a webpage devoted to lawn and garden care. On this page there are tips for harvesting and saving water, organic gardening, native plants, using trees to save energy, using less pesticides and herbicides, etc. GPLGE is very conspicuously absent.
An Interview with Austin Eischeid, Planting Designer
Describe your background a bit, and how you came to do planting design?
I started out experimenting in the vegetable garden as a kid. My parents wanted to show my sister and I where our veggies came from and I took a liking to it. I began experimenting with roses and found out how much work they were. I wasn’t willing to put in the time for dead-heading, watering through droughts, and treating them chemically. I was amazed to see entire sedum plants grow from a couple of cut stems, but I grew tired of them very quickly as my garden became overrun by sedum! I began experimenting with adding more annuals, perennials, and grasses, and the learning never ended. It was the only thing I could imagine going to college for, and it seemed I was destined to go to Iowa State University for a BS in Horticulture with an emphasis on landscape design.
While at Iowa State I heard Roy Diblik speak on perennials. His plantings were so vivid and inspiring, like nothing I’d ever seen before, and this was when I knew I had to become a planting designer. He spoke about his ‘Know Maintenance‘ approach to design, how there would always be some degree of maintenance, but that you had to really know your plants to build a sustainable plant community. Roy then became my mentor and introduced me to strong, hardy, long-lived perennials. For Roy, using perennials was about much more than just the flower; it was about overall texture and form for visual interest, winter structure, seasonality, and whether it behaved itself or not (for example, spreading or over-seeding).
by Michele Richmond, PLA, ASLA, SITES® AP, LEED® Green Associate
Can you plant a site with species that cause little to no allergies in patients? That was the specific request from our client for a site comprised of a community healthcare clinic and workforce and affordable housing. Many of our client’s patients are traumatized children with asthma and allergies. The goal of the building and landscape design was to create a safe place allowing for positive experiences for children coming to the clinic. In this context, a single allergy attack removes children from this safe space and can set back their recovery. So, what to plant?
Allergies and Asthma in America
Today, more than 50 million people in the US have allergies and asthma [i], including hay fever and respiratory, food, and skin allergies that can come from plants in our landscape. Allergies can be a onetime event or a constant reaction to pollen. Currently, allergies are the sixth leading cause of chronic illness in the US, resulting in 200,000 emergency visits a year [ii] and costing more than $18 billion annually [iii]. In Washington State, asthma is the most common chronic illness for low-income children. Asthma cases have doubled in the population at large and quadrupled among low income families in the last thirty years [iv].
While allergies largely cannot be prevented, we can lessen allergic reactions. As children, we learn to identify poison ivy and oak to avoid contact. As adults, we learn to check pollen counts [v] daily to determine if we need to take allergy medicine. We learn to identify and keep a healthy distance from plants that are the worst offenders to offset symptoms.
While plants are a primary color in the landscape architect’s palette, we often fail to grasp the complex challenges, laborious processes, and good luck it requires to bring healthy nursery stock to the market and ultimately to our projects. At the 2018 ASLA Annual Meeting and EXPO in Philly, the Planting Design Professional Practice Network (PPN) met to discuss the ever-important relationship between the landscape architect and the nursery grower. We heard from four nursery professionals to learn about the realities of nursery production, incoming production shortages, and how to foster a better relationship with your grower.
Nancy led off with an insightful presentation of the tree growing process. We all know that trees are an investment in time, but we may not fully appreciate the dedicated efforts that go into growing the trees we specify.
As Nancy says, “Growing trees is an exercise in patience and faith in the future. It takes a long time and many skilled hands to grow beautiful, resilient, durable trees that will cast shade for future generations. Bringing new and improved trees to the marketplace is a collaborative, multi-generational effort that takes even longer.”
On August 12, 2018, I attended a meeting of a new committee created by the Environmental Water Research Institute (EWRI) of the American Society of Civil Engineers (ASCE). The task force, comprised of approximately 40 stormwater professionals, is titled: ASLA/EWRI Committee on Plants and Soils Performance in Green Stormwater Infrastructure (GSI). The committee will produce recommendations over the next few years that will be distributed in a booklet and online. This work will be specifically focused on providing better research-based guidelines for soil performance and plant performance as an overlapping, interrelated system rather than as individualized elements. The committee’s goal is to provide guidance on short-term, medium-, and long-term practices to ensure that systems maximize performance.
Additionally, other sub areas such as biodiversity, maintenance, and soil microbial functions will be considered. The landscape architects on the taskforce will take the lead in addressing aesthetics and other social parameters that can support or impede acceptance of Green Infrastructure as an important component of place making.
The first phase of the task force’s efforts is to create an annotated bibliography as an indicator of where research is headed and to reveal significant gaps that should be addressed. The literature review phase is being organized by Harris Trobman, Project Specialist in Green Infrastructure at the Center for Sustainable Development and Resilience, The University of District of Columbia. The committee needs good research-based literature, especially as it relates to the performance of plants in green infrastructure. If you have a favorite book or article that you would like to share, please send it to me by December 1, 2018, and I will format it for inclusion in the bibliography. Currently, the bibliography is reflective of the vast preponderance of research that has traditionally come from engineers and scientists. Please free to contact me with questions and/or comments as well. If you would like to format the citation yourself, I can send an example.
Jim Urban’s recorded presentation “Urban Street Tree Planting: Correcting Myths and Misconceptions” is now available through ASLA’s Online Learning series. Hosted by the Planting Design Professional Practice Network, this presentation provides valuable information on best practice recommendations for urban street tree design.
Despite 35 years of research, books, articles and lectures, the profession still maintains many myths and misconceptions about designing with trees in urban spaces. Tree health is still at risk from all too common and obsolete design errors. This webinar will point out the most common of these errors, and provide best practice recommendations to develop truly sustainable urban landscapes. Based on the six most critical concepts of designing for healthy trees, this session will teach sound, science based designs, details, and specifications. Better informed designers will have the tools to incorporate science and sustainability principles into the aesthetic principles that guide the design of these important landscape spaces.
• Understand best practices related to urban street tree planting.
• Incorporate the six most critical principles to attain sustainability in urban tree design.
• Use the latest research findings to make decisions on soil options for urban trees.
James Urban, FASLA, ISA
Urban Trees + Soils
Planting Design Professional Practice Network (PPN) Meeting
Saturday, October 22, 12:45-1:30 PM
Jackson Square Meeting Room, PPN Live on the EXPO floor
At the Planting Design PPN meeting Saturday afternoon during the ASLA Annual Meeting and EXPO, we will discuss our PPN’s goals for the upcoming year, meet the members who have been shaping blog posts for The Field and plans for Online Learning webinars, and have an opportunity to sign up and volunteer to join the Planting Design leadership team. The short 45-minute meeting will also give us some time for a discussion about designing for intermingled plant combinations led by David Hopman, landscape architect, associate professor, and chair of the PPN, and Nigel Dunnett, Professor of Planting Design, University of Sheffield, UK. This is intended as a participatory event so bring your toughest concerns and best ideas to share about this important and emerging trend in planting design.
In addition to the Planting Design PPN meeting, there will also be a planting design-focused EXPO tour on Saturday, and the EXPO Reception featuring the PPNs on Sunday, 4:30-6:00 PM.
Planting Design PPN EXPO Tour (1.0 PDH LA CES/non-HSW)
Saturday, October 22, 9:45-10:45 AM
Tours will start from PPN Live on the EXPO floor
This post is about the maintenance decisions that can have a profound effect on the range of plants useful for an aesthetically qualified urban polyculture. Some of the issues are addressed in the spreadsheet that was presented in part 8 of this series. For example, relative aggressiveness will help determine if plants play well together or if one plant is almost sure to dominate. However, the discussion that follows is on factors affecting plant palette decisions that go beyond the intrinsic characteristics of each plant that is considered.
Polycultures of herbaceous perennial plants and grasses are low maintenance but will frequently be more useful for aesthetically qualified native urban polycultures if they are pruned two or three times a year. Just because a plant is native does not mean that it must be allowed to express only its non-maintained form. This is especially true when soil amendments and irrigation are used. Water, fertilizer, and soils that are richer than what the plant would normally grow in without human intervention tend to make the plants taller, fuller, and more aggressive than otherwise, and may even cause them to flop over, particularly when they are blooming. Selective pruning may actually bring their appearance and stature back closer to a “natural” state.
Another big advantage to selective pruning is that it broadens the range of plants that can fit the aesthetic criteria of a particular polyculture. For example, one of the best native plants we have for shade conditions in North Texas is Inland Sea Oats (Chasmanthium latifolium). It is tolerant of both drought and seasonal inundation, stays attractive throughout the year, and establishes and spreads very easily. However, with irrigation it can easily get 3-4 feet tall, which may not be a desirable trait in an urban polyculture where other lower plants could have a seasonal focus. By cutting Sea Oats in half early in the season, it can easily be maintained at 18 inches tall. Some of the plants can also be left taller as “scatter plants,” which is how we are maintaining the UT-Arlington polyculture featured in part 7 of this series.
Part 8 of this series detailed the rationale and methodology for extracting qualified native plant species for use in creating polycultures. This month’s post features a discussion of how to successfully combine the species into a low maintenance native polyculture that can take the place of a monoculture groundcover.
The 109 species selected for use in part 8 were sorted to find groupings unified by height, texture, line, color, or form. Two categories of plants were created for each of the main polycultures. The first is very aggressive groupings of lower plants that serve as the primary intermingled groundcover. The second group of plants for each polyculture are accent plants that are unified with the lower grouping by texture, line, color, or form, but also have a strong contrasting element that will show them to best advantage. These are either more transparent scatter plants or more opaque shrubby plants used more like rocks or small hill shapes.
Case Study: Extracting native polycultures for bio-retention structures at The Botanical Research Institute of Texas
Reconceptualizing a Plant Palette Using Native Polycultures
Part 7 of this series focused on small steps that can be taken by any planting designer that will gradually move their designs in the direction of aesthetically qualified native urban polycultures. This post begins the discussion of a more complex and rigorous approach that I used in North Texas. The complexity of the Dallas/Fort Worth/Arlington area of North Texas is confounding when considering the use of extracted native polycultures as design components. It is a sprawling and rapidly growing metropolitan area of more than seven million people that is larger than the state of Massachusetts.
The problems and opportunities associated with reconceptualizing nature in this non-temperate area clarify an understanding of the issues in other areas where integrating nature may not be quite as complex and problematic. A detailed discussion is presented below that illustrates a research methodology used to develop 10 contrasting native polycultures for ecological retention structures on the campus of The Botanical Research Institute of Texas (BRIT) in Fort Worth, Texas.
Using Research to Define Aesthetically Qualified Native Urban Polycultures in North Texas
In North Texas, as in many other areas of the United States, the information needed to extract a wide range of native polycultures is simply not available. Academics and research institutes have a unique role to play in developing this information as the following description demonstrates. This research is directed at a palette of plants for ecological retention structures (large scale rain gardens), but can also serve as a model that can be adapted for the plant palettes required for many other types of planting design in metropolitan conditions in the Great Plains of the United States and other biomes throughout the world.
In 1998 Leslie Sauer Jones wrote The Once and Future Forest: A Guide to Forest Restoration Strategies. Embedded within the book’s forward, landscape architect Ian McHarg implored: “We must participate, with action and all the experience we can bring” in order to attempt to reverse environmental degradation and we can no longer expect our actions to be reversed with inaction. He further suggested that we embrace, “important havens, such as the interstices of cities” as critical canvasses for habitat enhancement and expansion for our native plants and animals.
Within our cities, large, contiguous tracts of vegetation, such as urban forests and riverfront corridors, offer critical ecological value potential. However, in more densely developed fragments of the city, where landscape design increasingly occurs, researchers are discovering that purposely selected woody plants can similarly provide animal species with viable urban habitat. Conceptualizing the ecological value of these urban interstices may be a function of perspective, or scale.
Developing a Plant Palette that Balances Aesthetic Control, Environment, and Ecology
Developing a plant palette for metropolitan areas that moves beyond the native and adapted plant palette is a very challenging and necessarily a very long term proposition. The vast corporate, design, regulatory, and research infrastructure that has evolved to the current state of the art will change very slowly, as it has in the past. As with any innovation, it will first be seen as radical and even eccentric and there will be many stakeholders that will push back hard against the tide of change. There are a number of possible scenarios for moving forward towards a more resilient and ecologically and environmentally supportive landscape palette.
One likely scenario for the transition to a more balanced palette is an incremental approach that gradually introduces native species, varieties, and selections into the infrastructure of the green industry. This would be an evolution of the ‘native and adapted’ palette that has been emerging since the 1980s, perhaps accelerated by climate change and the ‘new normal’ of warmer conditions with wide swings in rainfall patterns, coupled with increasing water needs from a rapidly growing population. This evolving palette will represent the same basic approach currently used by many designers for the selection of plants. Designers will search for aesthetically pleasing groupings, or drifts, of discrete monocultures that meet the practical, aesthetic, and financial criteria desired, albeit in a more environmentally and ecologically sustainable way.
Soil structure (how soil particles are held together to form larger structures within the soil) is recognized as an important property of a healthy soil. Grading, tilling, soil compaction and screening soils during the soil processing and mixing process damages structure. Structure makes significant contributions to improving root, air and water movement thru the soil. Soil screening is extremely damaging to structure but is included in most soil specifications.
Why do we screen soils and what happens if we do not? Prior to the mid 1970’s soils were rarely screened and landscape plants performed quite well. Installed soil was moved with clumps or peds throughout the stockpile. In the last 15-20 years farmers who have stopped tilling their soil have found significant improvements in soil performance. Several new research projects suggest that elimination of the screening and tilling processes in favor of mixing techniques or soil fracturing that preserve clumps of residual soil structure may improve landscape soils.
We know that all good science is based on adequate data. And if you’re reading this page, you probably also already know there is a lack of adequate data when it comes to the real-world performance of urban tree planting soils. This post is your chance to change that and add your own information to a shared database of soil performance data.
A bit of background: In 2014 we (Eric Kramer, ASLA, and Stephanie Hsia of ReedHilderbrand; Robert Uhlig, ASLA, of Halvorson Design; Bryant Scharenbroch, PhD of University of Wisconsin – Stevens Point; and Kelby Fite, PhD of Bartlett Research Labs) undertook a micro-study of seven sites in Boston — constructed urban landscape projects anywhere from 5 to 45 years old. Each project took a pro-active approach to designed soil systems, using suspended pavements, Cornell University structural soils, or sand-based soils. We took soil cores, recorded soils horizons, took lab samples and compared findings to what we knew about what had been installed. We also assessed the performance of the trees over time.
Stem girdling roots, kinked roots, J roots, T roots, and root collars buried deeply in the root package are one of the principle reasons whey trees and large shrubs fail to recover from transplanting or decline and even die at a young age after planting. These problems are typically created in the nursery by practices that do not produce plants with radial root architecture and place the root collar close to the surface of the soil. As a plant moves thru the production process from propagation to delivery at the site, there are many opportunities for root problems to develop in the plant.
Most plants are started in small containers and then gradually moved into larger containers. If the plant is sold in a container there may be three or four different container sizes. Each of these containers may result in a series of roots circling around the edges of the pot forming circling roots. Any of the circling roots above the root color can eventually choke the tree. Other roots may be deflected from the bottom of the container and grow upward to the surface forming a sharp kink in a root that may eventually become an important structural root. If these misshapen roots are not pruned at each shift in pot size they form an imprint of constricting roots in the next container. As trees are repotted they are also often placed too deeply in the next pot. Trees lined in the field may also be buried in the soil. This places the roots too deep in the soil where oxygen is less available at a critical point in the trees development.
When high-intensity rainfall events roll through cities, particularly those with combined sewer systems, peak flows increasingly overwhelm grey infrastructure, compromise water quality, and induce sedimentation and erosion. New research suggests that engineered soil and purposely selected plants within green infrastructure may help offset these flows by offering more benefit than most stormwater engineering models and municipalities acknowledge.
A handful of progressive entities – like the Chesapeake Stormwater Network and the Commonwealth of Virginia – now award extra stormwater credit for management approaches that deploy high-performance engineered soils, dense and varied planting palettes, or an inter-connected series of green infrastructure elements. More research is needed, however, to mobilize engineers, designers, and policy makers to rely more heavily on the “green” in green infrastructure.
Part 5 of this series introduced three relevant strategies at the new George W. Bush Presidential Center that were employed to select future viable species of plants. The first two, using local plant consultants and recreating a local prairie ecosystem, are addressed in part 5. This month’s post will focus on the third strategy, using an aesthetically qualified native polyculture for large areas of turf at the Bush Center.
The idea of using a palette of indigenous (actual native) plants is currently largely the purview of a small, relatively sophisticated cadre of native plant specialists and enthusiasts. Reconciling two points of view—the desire to restore complete ecological ecosystems with their environmental and ecological benefits, and using native and other adapted plants with a more traditional design approach, requires a reconceptualization of natural plant communities within a cultural context.
This difficult problem must first be addressed at the macro scale by finding the most appropriate native ecosystems, within the overall biomes, that are most practical and useful for the extraction of species for a new environment, the ‘new nature’ created by development conditions in metropolitan areas. It must then be addressed at the micro scale by constituting the details of this new synthetic environment, the particular plant palette, so that it meets biological, cultural, personal, and environmental goals and achieves a better balance of the three areas of aesthetics, environment, and ecology. The native turf polyculture used at the Bush Presidential Center is a good example of using both of these strategies.
Part 5: Lessons from the Bush Presidential Center: Local Consultants and Urban Prairies
The G. W. Bush Presidential Center landscape is a good point of departure for a discussion of a variety of strategies for future viable plant palettes, as there were three relevant strategies employed for selecting plant species:
Using local consultants to check species for regional appropriateness,
Recreating a local prairie ecosystem in an urban context using ecological restoration consultants, and
Using an aesthetically qualified native polyculture.
The Bush Center is a 23-acre campus near downtown Dallas that features four distinctly different plant palettes. Almost the entire campus, designed by Michael Van Valkenburgh Associates, Inc., was designed with sophisticated sustainable strategies. A small internal Rose garden, however, uses a more traditional green industry plant palette and demonstrates a good balance of a small area of resource-intensive exotic species within a large, biologically diverse, resource-efficient landscape—with many species of native plants.
Part 4: Contemporary Native and Adapted Plant Palette
The rise in research and the popularity of using native and adapted plant palettes can be traced to the work of the Colorado Water Board in the early 1980s. They coined and copyrighted the term ‘xeriscape™,’ a combination of the word “landscape” and the Greek word “xeros,” which means dry. [1-2] Other terms have been created for similar approaches in other areas. In North Texas the term used by the North Central Texas Council of Governments is ‘Texas SmartScape™.’ According to their website, the program is designed to “Conserve water and save $Money$ on your water bills; beautify your home and local environment; attract native butterflies, hummingbirds and other wildlife; and prevent / help reduce storm water pollution!” 
The native and adapted plant palette has made a large improvement to the environmental cost/benefits ratio of using plants for ornamental horticulture. The prime driver has been water savings, a subject that many people can relate to, including people who are not focused on other environmental issues or who may be primarily looking to save money and reduce maintenance. The gardening approach using this palette is flexible and can even approach fine gardening standards while using far less resources. The focus of designs using these plants is usually still discrete monocultures, or ‘drifts,’ of single species of plants using unity and contrast techniques derived from traditional principles. There has been a trend in recent years towards more naturalistic intermingled plant combinations using this palette as well. It has been very well promoted by government, industry, the design community, and academia, thereby hastening the adoption of this important innovation. Plants that were very hard to find and very expensive a few years ago can now be found at very low prices in many big box retailers.
The native and adapted plant palette is currently the state of the art when it comes to a proven and commercially-viable environmentally friendly strategy for selecting plants. It is the one that the most forward thinking landscape architects and garden designers use. Some of the tenets have even been written into landscape ordinances in drier parts of the United States. It is flexible, cost effective, and there is ample information easily available to train designers for success.
Part 3: The National Green Industry ‘Utility’ Plant Palette
The next step forward in moving towards a better balance of aesthetics, environment, and ecology has flourished since the latter part of the 20th century with the introduction of better adapted plants by the national horticulture industry. These are the ‘workhorses’ used by landscape architects to cover large areas of ground in landscape development and to provide the structure and spatial definition desired for landscape designs. They are hybridized species of turf, groundcovers, annuals, perennials, shrubs, and trees that are rarely indigenous to the areas where they are planted. The massive scale of the areas in the United States covered by these plants makes them the primary target for the aesthetically qualified native polycultures that are the subject of this series. Turfgrasses alone cover over 63,000 square miles—about the size of the State of Florida—and may be the largest irrigated crop in the United States. 
As in part 2 of this series on fine gardening, the priorities of the companies and the plant palettes they produce are revealed by examining the search functions on their websites. These websites show what the companies want their customers to look for and, significantly, what is missing from the thinking that is reflected in the plant palettes produced.
Part 1 of this series, published earlier this month, explained the goal of promoting a plant palette that balances aesthetics, environment, and ecology. This installment begins the discussion of a variety of plant palettes and planting design approaches with ‘Fine Gardening,’ a methodology that is very out of balance with the goal of aesthetic, environmental, and ecological balance. Fine gardening is an approach where the artistic intentionality of the designer and the direct sensuous experiences for the user are often the only priority. This approach is used in many high end residential projects, botanical gardens, and other landscapes where cost is not a determining factor. For example, at the Getty Center in Los Angeles, the gardeners take the heroic measure of hand-snipping twice a month every third leaf of each branch of the London Plane trees that line the path of the famous Robert Irwin garden, per Robert Irwin’s precise instructions. Fine gardening is promoted heavily in many newspapers and in magazines such as Southern Living, Fine Gardening, and many others.
Part 1: Aesthetics, Environment, and Ecology in the Creation of Plant Palettes
Essays about plants usually focus on specific plants, specific approaches to combinations of plants, practical uses for plants, plants for specific habitats, etc. These essays are indicative of the broad and continually evolving way that landscape architects approach planting design. This post takes a step back to address the issue of how landscape architects should use a clear set of principles to inform their palette of plants. By thinking first about the plant palette, new approaches to planting design will emerge that reflect the contemporary concerns of both the profession of landscape architecture and society at large.
Many design firms have design priorities that can be summed up in a few words. The ideas are sometimes illustrated with Venn diagrams and referred to as a triple (or quadruple) bottom line. The three criteria that are the focus of this series of posts are aesthetics, environment, and ecology. Other important elements, such as community and economics, can be addressed with a plant palette that balances these three important criteria. However, if art or economics, for example, are the driving generators of a plant palette, it may not be possible to bring the plants into balance with environmental and ecological concerns. Ecology is the most difficult and complex parameter to bring into balance and is currently the leading edge of future viable planting design innovation for landscape architects.
A variety of approaches to the selection of plants will be tested against the criteria of aesthetics, environment, and ecology in future posts. These posts will begin with a critique of palettes that are the most out of balance and proceed to others that gradually bring the three elements into equilibrium. The end of the series will propose a methodology for creating a palette of aesthetically qualified native polycultures suitable for the typical kinds of projects undertaken by landscape architects in metropolitan areas.
Planting Design Professional Practice Network (PPN) Meeting
Sunday, November 8, 5:10-5:45 PM in PPN Room 3 on the EXPO floor
At the Planting Design PPN meeting Sunday afternoon during the ASLA Annual Meeting and EXPO, we will discuss our PPN’s goals for the upcoming year, meet the members who have been shaping blog posts for The Field and plans for Online Learning webinars, and have an opportunity to sign up and volunteer to join the Planting Design leadership team. We will have three very special guests at our event, who will make short presentations to the group and be available to meet and answer questions:
Noted plantsman and designer Roy Diblik has spent more than 30 years studying, growing, and enjoying plants. His passion for native plants and other perennials began with his work at the Natural Garden Nursery in St. Charles, Illinois, and has been cultivated through his establishment of Northwind Perennial Farm, a nursery in Burlington, Wisconsin.
Roy’s recent work includes a planting of the new Oceanarium at the Shedd Aquarium in Chicago and a garden for the modern wing of the Art Institute of Chicago. He is best known as the plantsman behind Piet Oudolf’s midwestern garden designs, including the Lurie Garden at Millennium Park in Chicago.
Jim Urban, FASLA Jim is well known for his skills in the areas of urban arboriculture and soils, including the preservation and installation of trees in the urban environment and the specification and installation of specialized planting soils for roof gardens, urban landscape plantings, and rain water management. Jim will present to the group about the TREE Fund, a non-governmental source of funding for research and education programs in the field of arboriculture.
Nancy Buley, Hon. ASLA
Nancy, Director of Communications at J. Frank Schmidt & Son Co., will speak about the health benefits of trees and green space with an emphasis on new research, and will share a handout with links to resources and research available on this important topic.
The third week in June is home to National Pollinator Week, a week that the U.S. Federal Government and the North American Pollinator Protection Campaign (NAPPC) officially set aside in 2006 to steer our focus toward the plight pollinators are facing. It’s estimated that a quarter of all invertebrates are pollinators and in the past 35 years, invertebrate populations have decreased by about 45%, while the human population has doubled (University College of London, 2014). In earth time, 35 years is about as long as it takes for a person to blink. If this much diversity can be lost that fast, our actions must also be as swift. Fortunately this year, all hands were on deck, from local parks departments all the way up to the President of the United States. But what was accomplished? And…is it enough?
Monarch populations are at a mere 10% of what they were just 20 years ago (Center for Biological Diversity, 2014) and domesticated honey bee stocks have decreased 58% in 58 years (National Research Council, 2007). In response, POTUS announced the release of an unprecedented action plan to call national attention to the population devastations happening to wild and managed pollinators. The White House Pollinator Research Action Plan outlines issues pollinators are facing and highlights priority actions for a cornucopia of public and private groups. This is the first administration to actively address the issue of pollinator decline to the public and that is a huge step. It is also following through with its promises of creating databases of more accessible information.
But the problem is the document is filled with words like “identify,” “understand,” “determine,” and “research.” The key word lacking here is “do.” How can this be called an action plan when it is missing key action words? Even when action is mentioned, some of the measures have existed for years already. These are not necessarily new advances to protect pollinators, but rather are a distraction from our relatively unbridled pesticide use and the paucity of suitable habitat as a result. I can’t say I am surprised though. When 25% of the global agrochemical market is neonicotinoids, you are bound to run into some red tape (National Resource Defense Council, 2014). Luckily, there are groups spreading the message to put pressure on the government to make big changes…and fast.
“Landscape design is the art that engages with all aspects of a sustainable world: elemental forces, materials, humans and other living beings. Thus it is the responsibility of landscape artists to create the work and develop the aesthetics that will make experiences of a sustainable world highly enjoyable and desirable.”
–Diana Balmori, FASLA, A Landscape Manifesto
In late March, the Friends of the High Line team began its annual “Spring Cutback.” For most perennial gardeners, and especially those who align themselves with the Piet Oudolf “New Perennial” aesthetic, the process of cutting back ornamental grasses and the skeletons of last season’s herbaceous perennials is as much a harbinger of spring as the first bulbs poking through the soil. In New York City this process is no different, as volunteers flock to the High Line to play a part in the preparation of the park’s plantings for another year of glorious, wild exuberance. This community event has quickly become a tradition that many New Yorkers mark on their gardening calendars, and it has particular relevance to landscape architects who are interested in creating well-maintained, long lasting, and luxuriantly planted urban environments.
The most limiting force exerted on planting design is maintenance. A recent ASLA survey of emerging trends for 2015 in residential landscape design emphasized “low maintenance landscapes” as one of the top consumer demands. Landscape architects often justifiably associate complex planting maintenance requirements with increased operational costs and consider it a potential obstacle to the long-term sustainability and viability of the landscapes they design. These constraints have spawned an exciting branch of planting design research in Europe, where pioneering horticultural ecologists like James Hitchmough and Nigel Dunnett at the University of Sheffield are developing seed mixes and modular planting systems that can be implemented in public spaces to provide an exuberantly diverse aesthetic spectacle with minimal maintenance involved.
These are indeed exciting developments and must continue, but what the High Line Spring Cutback illustrates is that there is another strategy to ensure diverse, ecologically functional and aesthetically engaging plantings thrive in urban public spaces. Rather than propose a planting like those being developed in Europe that thrive on neglect, the High Line’s model requires that the planting designer craft a vegetal environment that is so undeniably beautiful and easy to fall in love with that its life will never be in danger, regardless of economic circumstances.
Bees are one of nature’s biggest celebrities. They have been on the cover of Time magazine, written about in The New York Times, and featured in multiple documentaries with various celebrities. And there is good reason for it. Bees are responsible for the pollination of the majority of foods, including almonds, blueberries, avocados, and watermelons, as well as the pollination of many flowering landscape plants. Bees are a keystone species, and we need to rehabilitate their populations or face a serious change in the composition of our landscape and meals…which is not something I take lightly. Take away blueberries and avocados and I would have an anxiety attack. But my work is about much more than just saving the bees. It’s about biological design as everyday practice. It’s about changing policy and education to support the creation of living landscapes and not monocultures. It’s about diversity on all scales of life because diversity attracts diversity. And it all starts with bees.
Piet Oudolf’s planting designs for such high-profile projects as Chicago’s Lurie Garden in Millennium Park and New York’s High Line have created a definitive “new perennials” style that he describes as “romantic, nostalgic, not wild, organic, spontaneous” in an article in The Telegraph. His gardens can be recognized by their large sweeps or drifts of tall perennial varieties and more naturalized plant choices, which create blocks of color and texture that weave the eye through the garden. Veronicastrum, Sanguisorba, Cimicifuga, Miscanthus, Rudbeckia, and Eupatorium are several perennials that often populate his signature gardens.
At Hauser & Wirth Somerset, a new gallery and arts center in Southwest England that will open this July, Oudolf is further developing his style to include combination groups of perennials, grasses, and groundcovers in his stylistic development as a garden designer. Additional cultivars and variously scaled selections will be arranged in repeating clumps versus the usual expansive drifts.
The Planting Design PPN, chartered in 2012 in response to ASLA members’ interest in the subject, creates many opportunities for examining the area of planting design and horticultural selection within the bigger picture of categorical expertise in our profession. As PPN Chair, I am charged with seeking interesting contributions for The Field. So, traveling along the internet I came across a planting design style for a modern prairie picture that truly took my breath away! It turns out that garden designer Adam Woodruff, of Adam Woodruff + Associates in Clayton, MO, was able to travel extensively to develop his planting design style. Landscape architect Thomas Rainer found Adam’s work breathtaking, too, and in his spare time between teaching at the College of Professional Studies at The George Washington University and his position as Associate Principal at Rhodeside & Harwell, a leading national urban design and landscape architectural consulting firm, he’s written a great re-cap of Adam’s travels and professional thoughts. Check out Thomas’s blog, Grounded Design, for additional planting design-themed posts!
–Deirdre E. Toner, Affiliate ASLA, Planting Design PPN Chair