Boston’s Evolving Urban Wilds

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In the 1970s, landscape architect Elliot Rhodeside, FASLA, Rhodeside & Harwell, created a program with immense, lasting value for Boston: the 1,400-plus-acre urban wilds program. Not quite parks, urban wilds are in-between natural open spaces — wetlands, shorelines, hilltops, meadows, woodlands — saved from development. To this day, they have a “unique hybridity,” and are still not part of Boston’s official park system. In a session at the ASLA 2013 Annual Meeting in Boston, Harwell, the program creator; Paul Sutton, the current manager of the urban wilds at the Boston Parks and Recreation department; and Jill Desmini, a professor of landscape architecture at Harvard University’s Graduate School of Design (GSD), discussed the challenges involved in both preserving and maintaining Boston’s wild urban places.

Protecting Wild Beauty in the City

As a young landscape architect, Rhodeside said Boston’s wild urban spaces had a “profound effect on me.” He felt that “developing these natural areas was the wrong way to go,” because only in Boston can “someone walk out of their house and come across a Puddingstone rock cropping right in the middle of their urban backyard.”

To make conservation a reality, Rhodeside, who was then chief landscape architect for the Boston Redevelopment Authority, had to get a plan in place. After winning a $100,000 grant from the National Endowment for the Arts (NEA) with some $50,000 in matching funds from the city, Rhodeside began reaching out to the local communities to connect them to the vision. “The idea wouldn’t work unless we could tie it to the neighborhoods.”

Rhodeside said he was inspired by San Francisco’s hilltop parks, with their unique micro-climates. “These places provide relief from the city.” Palo Alto has these wild wetland trails. He also looked to Frederick Law Olmsted, Charles Eliot, and Ian McHarg for models.

At first, the goal was pretty conservative: to simply identify 10 sites with natural value, some 100 acres in total. But his team soon set-up a database and recorded all known threatened sites. Using an aerial photographic analysis, they covered the entire city. They decided to focus on “scenic, vacant land next to park lands, undeveloped land, vacant land next to water bodies, and highly publicized areas.” Combing the whole city, they discovered more than 2,000 acres of land possessing “scenic beauty and natural value.” If all these ecologically-valuable lands were protected, they would expand Boston’s park system by 50 percent.

The next step was to create an implementable plan. For that, they had to find out who owned what. Through their investigation, they discovered that the city already owned 25 percent of the prospective urban wilds. “They were just sitting there unprotected.” Collaborating with community leaders and the Boston Conservation Commission, they began pushing the city to protect those.

One advocacy tool was a “beautiful report” that was both “poetic and comprehensive.” A companion education piece was put up in Boston’s subway showing people how they connected to existing natural areas. Then, Eugenie Beal, a local conservation advocate, came in and set up a $250,000 line of credit from the bank to buy up urban wilds and then hand them over to the city. She created the Boston Natural Areas Network (BNAN), “accomplishing an enormous amount.”

Rhodeside said their efforts succeeded in saving 2,000 acres in part because the timing was right. “We were in a recession, so we had a respite from the development era. It was the era of conservation.” He added that a burst of “renewed interest in the great landscape architects of the past helped,” as did the new federal programs that were created in the 70s like the Environmental Protection Agency (E.P.A.) and others.

Managing the Wilds Without a Budget

After BNAN was set up, it became “extremely active,” said Sutton. Through the 80s and 90s, the program became “adept at purchasing private property and transferring it to the parks department.” But while there were victories, with large parcels added to the network of wilds, the overall condition of these natural places declined, all the way through the 90s. This decline began with the economic downturn in the early 80s and statewide tax cuts. The result: “There was no maintenance, and lots of graffiti, litter, vandalism, drugs, and invasive plants.”

Still, one victory was purchasing Allandale Woods in West Roxbury, some 100 acres of forested wetlands near the Arnold Arboretum. Another was adding 25 acres of woodland near Hyde Park. To connect Boston’s MBTA transportation system with the Arnold Arboretum, the arboretum was given Bussey Brook Meadow, adding another 25 acres.

In the 90s, the city hired a urban wilds consultant who focused the parks department on creating a master plan for these places. Then, beginning in 2000s, there was a renewed effort to purchase and set aside ecologically-valuable land. The city got Belle Island Marsh, “one of the most ecologically-productive systems in the city,” a wetland that is being further restored.

Nira Rock was renovated. “It’s a success story.” The urban wilds program “piggy-backed of a nearby playground restoration,” leveraging the activist neighborhood. There has also been a “subtle, hidden restoration of larger sites,” multi-year initiatives that involve a real “hodge-podge” of local groups. Volunteers now deal with invasive plant removal and trail improvements throughout the system of urban wilds.

Sutton said the urban wilds program is “still a stepchild. We can’t use the park system logo.” There’s no budget, given most of the parks department’s finances go to active recreation areas and historic parks. “We have to market ourselves to the city.” But he said realtors are starting to see the value of the restored areas. And universities and non-profits are getting involved.

Within an increasingly revitalized system, the big challenge remains how to deal with sites spread all over the city and “getting new stewardship groups formed.” For the future, he wants these urban wilds to be “fun, inviting, and accessible,” but he also worries about how the city is going to “market these spaces to the next generation” so they remain valued.

Redefining These Places as Novel Ecosystems

Desmini, who teaches landscape architecture at Harvard University’s Graduate School of Design (GSD), said there were 143 urban wilds covering some 2,000 acres in 1976. In 2010, there were  just 105 wilds covering 1,414 acres. Of that, 785 acres are permanently protected.

She said in the Allston / Brighton areas of Boston, “lots of urban wilds were lost.” In East Boston, segments near the airport are also gone. Other sites have been “dramatically transformed” over the past 40 years. Many places now have a “unique hybridity.”

Desmini said the definition of an urban wild has also changed over the years as these places have evolved. “Urban wilds are not parks or wilderness,” but something in between. Urban wilds are “unorganized scraps of nature,” celebrated for their “indigenous qualities.”

Urban wilds are “places of natural beauty and reflect a history that predates the American revolution.” They are a living story of “urban ecology and abandonment.” These are spaces “where nature instead of man shapes the space,” yet humans’ influence is still felt. They can be defined as novel ecosystems.

As with any novel ecosystem, they will not be pure, but they can still be celebrated. They have an “openness,” so they can be viewed as either “orphans or opportunity-filled.” They are rich with “vegetative succession and continuously evolving.” They can also have different hybrid uses. As an example, she pointed to an urban wild in Berlin where the local authorities actually allow graffiti spraying during certain hours.

Today, preserving an urban wild is about “conserving spontaneously-vegetated sites.” She said the future will be about “innovative maintenance” that takes into account the unique qualities of these spaces.

She said it’s also important the city starts treating the urban wilds as a comprehensive system of novel ecosystems. “The city can amp up the hybrid qualities.” Otherwise, they will “continue to struggle with fragmentation.”

Image credit: Allandale Woods / Boston Exotic Flowers

Tree Gardens: The Largest Living Architectural Structures

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Tree Gardens: Architecture and the Forest
by Gina Crandell, a landscape architect and professor at Harvard University Graduate School of Design, is a fascinating exploration of what she calls the “largest living architectural structures” – masses of trees that form expressive spaces. Crandell provides an in-depth study of several iconic landscapes and the role of tree planting within the design of these world-famous spaces. Tree Gardens combines rich historical research with careful design analysis to illustrate an array of living structures, many of which offer defining concepts central to landscape design.

Case studies from the Renaissance era to the modern-day reveal the goals of the original designers and how the projects have since been maintained. The legacy of each project is discussed in detail, as the removal and replacement of trees within these influential and often beloved landscapes is inevitably costly and controversial. These discussions provide an excellent framework for the book’s primary focus: the spatial strength of tree forms and their crucial relationship to the definition, connection, and continuity of spaces.

The case studies cover the historical era (Lucca and Boboli Garden, Italy and Versailles), the era from 1860 to 1960 (Central Park, Gateway Memorial Park, and the Christian Science Plaza), and more recent projects spanning 1995-present (Tate Modern, Reimer Park, Novartis Headquarters, Brooklyn Bridge Park, and the 9/11 Memorial Forest). In the case studies, historical background, views on art and gardens, and the significance of the design concepts set the tree structures in a rich context.

The reader gains an understanding of the significance of various landscapes in the evolution of design. For example, we learn how Versailles challenged the traditional boundary of garden and regional landscape with its unprecedented scale and ambition.

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We learn how the naturalized forms of Central Park reflected not only impressions of Olmsted’s trips to Europe and England, but the idea that forms free of rigid geometries represented a new found freedom.

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We learn how artistic representations of gardens influenced people’s perception of nature, and the Musical Garden by Sorensen, inspired by the Danish agricultural landscape, pushed the boundaries of geometric and spatial ordering.

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We also learn how Dan Kiley’s revolutionary emphasis on proportion and the critical nature of tree spacing would make him the father of the modern bosque.

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The book then provides a cross-section of the cultural, social, and political factors that influenced not only the garden designs but the prevailing public perceptions of the time. Particularly enriching is the dialogue on the “garden as art and forest as architecture” and the evolving perception of man’s relationship to nature.

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This captivating analysis provides a great reference. Throughout, Crandell analyzes all sorts of tree structures: allees, bosques, palisades, groves, quincunx, plantations, thickets, and their ability to transform space over time. The guiding principles and design theories behind these iconic landscapes offer a wealth of information for designers to consider in future projects.

Read the book.

This guest post is by James Royce, ASLA, LEED AP, Principal, Studio2112 Landscape Architecture.

Image credits: (1) Princeton Architectural Press, (2) Historic Photo of Central Park, (3) Musical Garden, (4) Versailles, France, (5) Rendering by Dan Kiley, (6) Orchard, Nursery, Garden. (2-6) Courtesy Princeton Architectural Press.

Permaculture = Permanent Agriculture


That’s at least one definition of this innovative practice, explained Jillian Hovey, the Toronto-based head of Sustainable Living Network at the 2012 Greenbuild in San Francisco. Another possible definition: “a holistic design methodology to access the intelligence of natural ecosystems.” Really, the goal of the ever-growing tribe of permaculturists is to “co-create with nature.” Permacultural projects include organic food, edible landscaping, forest farming, and other small forms of urban agriculture.

Hovey said one of the central tenets of permaculture is regenerative design. While sustainable design involves simply mitigating the negative impacts of humans on the planet, regenerative design goes beyond and seeks to create a “positive role for people on earth.” Practitioners of permaculture seek to merge landscape, people, and technology to create “food, shelter, and energy.” Hovey said it’s a “philosphical approach to land use” in which “intricately conducted ecosystems, consciously designed” are put to work. (Still, she said some critics argue that, in these permacultural systems, humans are at the center of the regenerative effort, so the approach is still too human-centric, and doesn’t truly benefit “life in all forms,” as permaculturalists say they do).

Bill Mollison, the Australian founder of the movement, wrote Permaculture: A Designer’s Manual, back in the 1980s. Early permaculturalists  in Australia wondered whether it could actually be replicated in other places, but they decided that other temperate climates could make the systems work. So a slew of Australian books came out, followed by American and European guides. Recent how-to literature includes Designing and Maintaining Your Edible Landscapes Naturally and Edible Forest Gardens.

Standing on Greenbuild’s oddest “dog-bone”-shaped center stage, Hovey walked in circles showing off photographs of permaculture projects being designed and built. One practitioner she showed, Austrian outlier Sepp Holzer, is well-known for his “crater gardens,” stepped, terraced landscapes, which involve moving earth to dig out gardens, creating more surface area for agriculture and microclimates for different plants.

Holzer was recently brought in by Hovey’s group to help build a stepped crater garden at a school in Detroit. With the use of a translator, Holzer communicated to the bulldozer operator to create a set of steep walls out of the earth, adding in wood joints made of out sticks to “increase the productive edges.” Wood was also put in so that it decomposed and made richer soils. Once the area was seeded, straw was put on top. As Hovey described, “nature hates bare soil. Weeds happen when soil is left bare.”

The project, and others like it, demonstrate how “nature can be used as a model.” Hovey said permaculturalists use a design process wherein “everything is connected, every function should be supported by multiple elements, and every element should serve multiple functions.” This type of design process “builds in redundancy and resiliency.”

Permacultural design also enables feedback to be incorporated throughout the process. “This is a cyclical, iterative, spiral approach.” This kind of approach allows permaculturalists to “eliminate pollution.” While waste is abundant in nature — because it produces so much — pollution is not. Pollution is the “concentration of waste to such a degree that nature can’t handle it.” Interestingly, Hovey said lawns are a form of pollution because they “suppress existing ecosystems.”

Hovey went into great detail on the benefits of compost (if done right, it shouldn’t smell), along with the application of permaculture in parks, small urban plots, and even windowsills. 

Closing with a thoughtful take on regenerative design, Hovey argued that if these systems are designed to be self-sustaining, “the agricultural output is theoretically unlimited.” And if designers understand “ecological succession,” these landscapes can be “self-maintaining and even replicating.” Hence, permaculture as a state of permanent agriculture.

Check out Sepp Holzer’s book on permaculture at the small-scale.

Image credit: Powell Street Promenade, San Francisco / Hood Design / image copyright Marion Brenner and Beth Amann

Measuring the Benefits of Urban Forests


At a Casey Trees‘ conference on urban forestry, David Nowak, Ph.D, research forester at the U.S. Forest service, one of the world’s foremost experts on urban forests, and a member of the team that won the Nobel Prize at the Intergovernmental Panel on Climate Change (IPCC), said out of the 20 biggest cities in the U.S., 17 have declining urban forests. “Tree cover is going down.” For example, researchers have found that D.C.’s urban forestry cover decreased by 1 percent in the last 20 years, while impervious cover (hard concrete) grew by 20 percent. Now and in the future, the key to boosting urban forests may be to make better use of innovative Web applications like iTree, which “estimate value and benefits” of the tree canopy.

Nowak said to really understand urban forests you have to look at their extent or structure. You have to know “how many trees you have and where they are.” The structure of an urban forest also impacts the benefits. For example, where trees are placed impacts who receives the environmental, psychological, and social benefits.

Forests can be measured in either a “bottom-up” or “top-down” manner. Bottom-up approaches involve counting species on the ground and looking at species, tree health, and the various health risks. Nowak and his team at the Forest Service participated in developing iTree, a bottom-up tool that helps manage forests. Top-down efforts are usually satellite-driven and involve high-resolution imagery and photo interpretation.

In an examination of urban forests, Nowak found that some 30 percent of vegetation is planted, while the other two-thirds is “naturally regenerating.” There are also varying levels of natural vegetation within key spaces in cities. In residential areas, the share of naturally-regenerating nature is relatively low because people plant or mow, while in parks and open spaces, it’s higher.

Invasive plants are also on the rise across the country. In D.C., invasive plants may even be shifting the composition of the forests. “Frontier plants are changing things.”

To track all this change, Nowak said it’s important to use tools like iTree, which can help local urban policymakers, planners, and landscape architects “better understand the canopy and the true value of ecosystem services.” Nowak said anytime you’ve heard a number about the dollar value of an urban forest, it was probably based in an iTree estimate. Using “local variables such as energy, air, water quality, and climate,” iTree can put a value on an area’s trees and help local policymakers optimize the performance of the forest.

While landscape architects and others understand the inherent value of trees, local programs to protect trees from pests and fungus are expensive and budgets are tight, so “we need to build the financial case.” Without “data and tools, it’s hard.”

With 20 years of data available, there are a number of applications where you can run and test models. iTree Canopy uses Google Maps to create statistically-valid estimate of tree cover, while iTree Species helps users identify the specific ecosystem service benefits of one tree over another. The system has about 5,000 trees in its database. iTree Hydro looks at tree canopy and stormwater, while iTree Design, which Nowak called the Sim City of landscape design, helps landscape architects and designers figure out the benefits of certain tree sizes and types in a landscape design. In the same way, the tool could be used to figure out the amount of financial benefits that are lost when a tree dies.

iTree 5.0 will include some new features like Google Maps, web-based data collection using mobile devices, the inclusion of data on the volatile organic compound (VOC) output of trees, and “benefit forecasting.” There will also be more data on “the risks each tree type faces from insects and diseases” as well as risks from a given forest structure. For example, too many species in one place means that part of the forest could be simply wiped out with an infestation, creating a vulnerability in the overall structure.

On the value of having a tool like iTree itself, Nowak said: “This is really about urban forestry technology transfer” through a “credible, USDA-approved, public domain software.”

For more on the benefits of urban forests, see ASLA’s animation: Urban Forests = Cleaner, Cooler Air. Nowak was an expert advisor on the animation.

Image credit: Aerial View of Logan Circle, Washington, D.C. / Wikipedia

Bridging the Divide Between Man and Nature

The Cultural Landscape Foundation (TCLF) and Central Park Conservancy are hosting a conference on October 5 in New York City called Bridging the Nature-Culture Divide II: Stewardship of Central Park’s Woodlands. The conference will focus on the challenges involved in crafting a sustainable future stewardship program for Central Park’s woodlands, but also leap off into interesting debates about man and nature in urban parks, tackling issues at the heart of what landscape architects do.

The woodlands, writes TCLF, may appear “feral” but are actually a “historic designed landscape.” In today’s world, with the focus on climate change, TCLF and the Central Park Conservancy wonder what it means to sustainably manage such a seemingly wild place, a landscape Olmsted described as representing “the superabundant, creative power of nature” but found at the heart of a great city.

TCLF writes: “The 843-acre Central Park, originally designed by Frederick Law Olmsted, Sr. and Calvert Vaux, with a succession of additions and refinements by Samuel Parsons, Jr., Michael Rapuano, Gilmore Clarke and others, is also host to 230 bird species, along with turtles, fish, and countless species of butterflies, dragonflies, and other insects.” Focusing in on the park’s great man-made woodlands in particular, TCLF writes that they are “among the most historically significant designed landscapes in the country, they provide valuable refuge for wildlife, and they are a vital recreational resource for New Yorkers.”

But, given these places aren’t wild, how should they be managed? TCLF and the Central Park Conservancy see a new approach: “When we expand our definition of ecology to include people and cultural values and recognize that human activity is part of any ecosystem we touch, the question becomes not ‘how do we strike a balance between nature and culture?’ but ‘how to do we interact with nature in a way that is both meaningful and sustainable?'”  

The one-day symposium will feature panels of officials from New York and San Francisco along with landscape architects and environmental designers from the around the country. The discussion will zoom in on the specific challenges involved in woodland restoration and management in Central Park, but panelists will also look at other cases from around the U.S. exploring design, management, and stewardship, and “how their lessons can be applied to Central Park’s woodlands.” 

TCLF conferences attract some of the best landscape architects, both as speakers and attendees. Moderators and speakers include Christian Zimmerman, FASLA, Vice President for Design & Construction, The Prospect Park Alliance; Elizabeth K. Meyer, FASLA, Associate Professor, University of Virginia, School of Architecture, Landscape Architecture; Dennis McGlade, FASLA, President/Partner, OLIN; Margie Ruddick, ASLA, Margie Ruddick Landscape; and Keith Bowers, FASLA, Biohabitats. See what they will be discussing in more detail.

Register for the symposium on October 5.

For those who can’t make the conference but will be in NYC, there’s no excuse to miss out on TCLF’s free What’s Out There tours, which follow on October 6-7.  The 25+ tours in all five boroughs are led by landscape architects, designers, and other professionals. TCLF writes: “Some are places we see daily, while others are ‘hidden in plain sight.'” Some great ones include the Noguchi Museum in Queens; The Cloisters in upper Manhattan; Van Cortlandt Park in the Bronx; multiple Prospect Park tours in Brooklyn; and Snug Harbor in Staten Island. The Weekend is organized in cooperation with the New York City Department of Parks & Recreation, the New York chapter of the American Society of Landscape Architects (NY-ASLA), Archtober 2012, the Central Park Conservancy, the Municipal Arts Society, the New York Restoration Project, New Yorkers for Parks and Open House New York.

Image credit: Central Park Woodlands / TCLF

In D.C., New Eco-District Plans Unveiled


After two years of internal debate among 17 different federal agencies and the D.C. government, the National Capital Planning Commission (NCPC) released its long-awaited plans for a new Southwest Eco-District designed to undo the worst damage of the massive “urban renewal” projects inflicted on L’Enfant neighborhood over the past decades. Designed to transform the spooky, almost pedestrian-free area just south of the Mall into a highly sustainable, people-friendly cultural and business destination, the Eco-district plan means to take on many challenges at once. As Elizabeth Miller, ASLA, the intrepid landscape architect who is guiding the project, explained, this 110-acre, 15-square block project is meant to showcase “high performance buildings and landscapes” while creating space for 19,000 new federal workers and solving some of the worst pedestrian access problems.

At the beginning of the hearing today, NCPC Chairman L. Preston Bryant, Jr said the project can go a long way to “breathing new life into the city.” While the whole Eco-District may take 20 or 30 years to design and implement, “we have a once in a generation opportunity to make this happen.” He added that NCPC and its many federal partners are eager to move forward because there are some synergies that make the timing right: The Department of Energy (DOE) building is “coming to a lifecycle decision,” meaning that it’s ready to be torn down because it’s now highly inefficient in terms of energy and water use; the Southwest waterfront plans are moving forward, with $2 billion in private sector investment set; and the D.C. government-led Maryland Avenue redevelopment project is on its way.

Miller outlined a vision for an Eco-District that provokes the imagination, at least among sustainable designers. She said the new District will “capture, manage, and reuse water, energy, and waste” and work beyond a single building, leveraging clusters of buildings to create a new system. At the same time, the plan will take aim at the incredible lack of public access — the barriers, the highways, and grade changes — that keep people away, except for the federal workers that have to go there for work.

Diane Sullivan, sustainability planner for NCPC, said a sustainable mixed-use community will arise out of a set of new “guidelines, objectives” that will frame neighborhood development efforts and the creation of new environmental systems.

On developing the neighborhood, Sullivan said that a user survey of D.C. residents found that the lack of amenities was the overwhelming reason why people didn’t want to move down there or even hang out there. So the goal is create a new tree-lined 10th street (or L’Enfant Place) that can connect the Mall to the new Southwest waterfront development while also making that connection itself an exciting cultural destination, lined with 1.2 million square feet in new space for up to 5 new museums, along with farmers’ markets and other draws.


Better pedestrian access is also key to making all this work. In the new plans, Miller said Virginia and Maryland Avenues will re-appear, carving new paths through new buildings as park-like avenues for promenading. Sullivan said the new local street designs cutting up the mega-blocks are still being worked out. She asked, “which streets should be monumental? Which should be local?”

To better get those pedestrians — all those federal workers — to the area, a “better inter-modal system” will be put in place, with a revamped, solar roofed-L’Enfant station, offering both commuter rail and Metro. To ease pressure off Union Station, more commuter rail may be directed there somehow.


The saving grace of the scary L’Enfant Place now is the fountain in Dan Kiley’s Modern-era Benjamin Banneker park, with its dramatic overlook across the Washington Channel. Unfortunately, the rest of Kiley’s park was not well realized. With spaghetti loops of highways cutting through, it’s a matter of taking your life in your own hands to go from the park to the waterfront. In the new plans, Kiley’s park will be completely redone but the area will still serve as a monument to African American surveyor Banneker. The new, more sustainable park will more easily connect to the waterfront while providing a new visual identity for the “eco” part of the district.


Now, on the systems that will make the district more eco: First, many of the old federal buildings will go, getting a revamp so they meet the goals of Obama’s Executive Order 13514, which calls for federal agencies to reduce greenhouse gas emissions, water and energy use. The ones that stay, like the famed Brutalist HUD building, will be updated to be more efficient.

Sullivan said the goal is to have “zero-net energy district as measured in carbon.” Pretty near impossible unless fully renewable power is the rule for the new Eco-District. Sullivan said solar PVs and solar thermal systems (for hot water) will be added to the roofs of the new buildings wherever possible, while ground-source heat will also be tapped. A central facility run by GSA, which runs on natural gas, will still be used (but that won’t get them to zero emissions).

Heading down towards the water, the freeway that cuts off the connection between Benjamin Banneker park and the waterfront will be capped with a new layer covered in solar panels.

For water, the goal is to reduce potable water use throughout the Eco-District by 70 percent and manage all stormwater where it falls. All building greywater will be reused while blackwater will go to the new anaerobic plant. Rainwater will be caught by acres of green roofs (including edible ones), green streets, trees, and planters. What isn’t caught will be funneled into cisterns underneath 10th street and used later. Green infrastructure is then clearly a central part of the strategy. Permeable areas overall are to grow to 35 percent, while the tree canopy is to reach 40 percent (a solid target). (Right now, the barren area has just 8 percent tree cover). While we didn’t hear anything substantive about creating a wildlife-friendly landscape designed to attract diverse species, we hope that’s in the works.


There are more ambitious goals for waste reductions: Some 75 percent of construction materials for the new buildings will be reused, and 80 percent of everyday waste will be diverted from the landfill. A composting program will be put in place, too.

So, how will this all actually work? Sullivan sees some government buildings first getting a light rehabilitation and then others will undergo a full rehabilitation. Three federal buildings will be “re-purposed” as major infill development begins. Then, big redevelopment will start over the freeway. At the same time, critical projects like a new Banneker park and a new 10th street landscape will begin next year.

What’s this all going to cost? Miller and Sullivan said an economic feasibility study only provided some high-level numbers, but they did say the federal government would make back its multibillion dollar investment over 20 years through reduced energy, water, and waste fees; increased revenues from private sector developers; and improved local tax gains.

While we hope this project is a sure thing, new governance structures and partnership and financing agreements will need to be worked out among all the partners, including the private sector developers who are key to making this all happen. Let’s hope this is not a protracted process. As the Eco-District gets moving, it can become an innovative showcase for how to revamp government hubs across the U.S.

Learn more about the bold plans. D.C. residents can attend a public hearing on the proposals on July 19. The comment period will be open for three months. Comments will be incorporated into a final plan ready to go by early 2013. By the end of next year, NCPC hopes to have design competitions launched for a new Banneker park and 10th street, its two priority public projects.

Image credit: ZGF Architects, courtesy of NCPC

D.C. Offers a Bold Vision for a More Sustainable Future


At a historic church in the Shaw neighborhood of Washington, D.C., Mayor Vincent Gray said there are either two future directions for the city: “The gaps between us could further divide our city,” or the city could become “greener, more equitable, and more prosperous” for all. Outlining a bold vision for a Sustainable D.C., Gray said he wanted the city to not only be the greenest in the U.S. but among all world cities. D.C. is currently ranked 8th in a recent ranking of North American cities by the Economist Intelligence Unit so the city has quite a ways to go to get to number one in this continent, let alone the world. In the near term, can D.C. beat New York City, Vancouver, or San Francisco? That’s a stretch and only possible with deep collaboration with the non-profit and private sectors.

Gray is giving the city one generation — 20 years — to accomplish his ambitious objectives, which weave in health, economic, employment, and environmental goals. The idea is that D.C. will not only become greenest but healthiest, with the most number of green jobs. On top of this, Gray wants to continue to grow the city’s population in a big way. Gray said “sustainability will need to be a continual process.”

In terms of carbon dioxide, the city wants to cut emissions by 50 percent by 2032. In presenting the goals, Christopher Tuluo, head of D.C.’s Environment Department, said “climate change is happening. If someone says it isn’t, they are flat out wrong.” A key part of achieving this goal will be reaching objectives on energy use and efficiency. The city seeks to cut district-wide energy use by 50 percent while increasing renewable energy use to 50 percent. Given some 75 percent of emissions come from buildings, the District will push for adaptive re-use of old buildings so they can become greener. The idea is to maintain and improve the current building stock and increase the number of LEED buildings (the city is already number one for that metric). Another way to fight the effect of climate change: strengthening D.C.’s already considerable urban forest, which stores much of the city’s carbon, reaching a 40 percent tree canopy by 2032. Here Tuluo added that “trees are important when it’s 100 degrees out because of climate change.”

Investing in more sustainable transportation systems is also key to both reducing transportation-related emissions and adapting to a carbon-constrained world. The district seeks to make 75 percent of all trips walking, biking, or transit in 20 years. Harriet Tregoning, D.C.’s planning director, said “this is a stretch goal but these trips already make up 50 percent of all trips right now.” She discussed how more young people may be moving to D.C. because the city’s transportation system is so affordable. This younger generation is so in debt with college loans they can’t afford cars. In fact, just 60 percent of D.C. residents own cars and that number is falling.

Sustainability means improving D.C.’s waterways, which are amongst the most polluted in the country. Gray wants 100 percent of District waterways to be fishable and swimmable, and 75 percent of D.C.’s green space to be used as green infrastructure that captures and filters rainwater for reuse. Tuluo wants the city to become much “spongier.” He wants the city to become “a much more natural place — not just for the environmental benefits. We want return on investment” in terms of stormwater management benefits.

The process for dealing with waste, which the Economist Intelligence Unit report said was among D.C. weak points, will need to be totally transformed if the city is going to reach zero waste in 20 years. Tuluo asked, “is zero waste a pipe dream?” Perhaps not. Organic waste is already turned into compost as a matter of practice in San Francisco, one of the best cities at dealing with waste. He sees D.C. residents “becoming urban farmers,” using their compost daily, and other waste consumed by digesters that turn other garbage into energy.

The front end of the reuse chain is local food production, which will also need to ramped up if the 75 percent of all food is to be grown within a quarter-mile of the population eating it. Tregoning argued that “it used to be really difficult to find a supermarket in the District.” While that has changed, improving the availability of local produce will be sped along by a network of food-productive roofs. She wants one million square feet of these vegetated roofs in place funneling produce to local shops and co-ops. (According to Gray, the city is already number-one in terms of green roofs so this may be possible). Getting local produce to D.C. residents seems to be a key focus. Health must be at the top of a sustainability agenda in a city where 22 percent of the population is obese. Gray wants to cut that rate in half in 20 years. 

D.C.’s plan won’t work without more equitable economic and employment growth. Right now, the unemployment rates in the city differ dramatically from ward to ward. In Ward 3, it’s as low as 2 percent, while in poorer parts of the city, like Ward 8, it’s 24 percent, among the highest in the country. Gray wants to boost the number of green jobs by five times — providing opportunities at all levels, from the PhDs experimenting with biofuels to the landscape architects designing parks, from the green roof installers to the maintenance crews keeping green infrastructure and waste reuse systems working.

Explore the plan. There are a few short, medium, and long-term actions listed. As Tregoning said, “the vision is a painting of what’s possible in the District.” A design and implementation strategy with hundreds of actions comes next. To see some actions that should be considered, explore ASLA’s 30-page set of recommendations: Becoming Greenest. One big focus of ASLA’s report was the need for a climate adaptation plan. If local species in D.C.’s great urban forest were to die off due to higher temperatures, none of the other goals related to water, air quality, or health will be possible.

Image credit: City Center, Washington, D.C. / SWF Institute

You Can’t Fool Mother Nature but You Can Understand Her


James Urban, FASLA, noted soil and tree expert, recently gave his talk, You Cannot Fool Mother Nature but You Can Understand Her, at the Arsenal in New York City. Urban is a prolific writer and lecturer on the subject of tree planting and the conditions needed to improve tree performance in urban environments. Urban focused his talk on “eight simple ideas,” all basic steps to yield more productive growth in urban trees. The ideas were driven home by a slideshow containing images from his recent award-winning planting guide and bookshelf mainstay, Up By Roots: Healthy Soils and Trees in the Built Environment. It was refreshing to know that the lecture did not fall on deaf ears as heads of the NYC Parks Department, the ASLA NY Chapter, and New York Restoration Project were all in attendance. If anyone needs to hear Urban’s talk, it would be them.

To Urban, planting trees is “all about the science.” Take a walk down your street and notice the adolescent trees stuffed into the recently curb-cut sidewalk. According to Urban, that is our fatal mistake. “We try all the time [to fool nature] but we never win.” The space below the ground is competing with other urban systems: stormwater structures, utilities, urban compaction systems. These obstacles severely hinder the performance of those adolescent trees, many of which were not even properly selected in the first place. Urban shared his understanding of this paradigm: “Once we have a hypothesis, we tend to give extra weight to any information that supports that hypothesis.” To Urban, this kind of thinking leads to many street trees being planted incorrectly.

Over the past thirty years, Urban has been instrumental in the development of both structural soils and structural cells for use under sidewalk pavement. However, his message has remained and his eight guiding principles to planting trees have as well:

1. Trees need dirt!
2. Plant trees that are native to their urban ecosystem.
3. Can you resolve the conflict between the politics of trees and the planting of trees?
4. There is no free lunch.
5. Get just one tree right.
6. More soil volume please.
7. Harvest stormwater.
8. Improve the nursery stock.

1. Trees need dirt!
According to Urban, New York is actually a relatively easy place to grow trees. To become a functional, mature tree in an urban environment, a tree needs between 800 and 1,200 cubic feet of “good-quality loam soil.” Urban believes that New York City has the space but not the soil.

2. Plant trees that are native to their urban ecosystem.
To further understand this concept the audience was pushed to buy Peter Del Tredici’s, Wild Urban Plants of the Northeast: A Field Guide. No longer are we harking back to the Manahatta planting plan for advice on what to plant on Queens Boulevard. Urban, the consummate pioneer of the urban environment tried to incite the crowd. “Let’s get into it and start figuring it out!” Urban also warned us that in ten years or less we will all be calling nurseries to purchase Ailanthus.

3. Can you resolve the conflict between the politics of trees and the planting of trees?
Urban took this opportunity to speak of the role of the arborist. Currently, certification is relatively easy to obtain. However, as the profession of arborists progresses it needs “serious restrictions.” Making certification more difficult to acquire would promote the profession, putting them on the political map. Arborists could then better join broader political discussions and highlight the importance of trees.

4. There is no free lunch.
Here Urban stressed the idea of compost. His example that “two tons of raw wood only produces one ton of compost” is telling in that he believes there is room to explore this area. He further explains this idea by bashing “the hot item right now,” Bio-Char. After describing Bio-Char as “really bad,” he lightened the assault by clarifying that “it is only good for small amounts of soil.” I wonder if this “simple idea” was an idea at all, or an excuse to diminish the popularity of the charcoal-based soil amendment.

5. Get just one tree right.
In a checklist for tree design, one requirement is to understand the root area index (RAI), the calculation determining the correlation between the root and the surface area. To explain this, Urban used an image of a wine glass standing on a dinner plate. The dinner plate, representing the soil volume and the wine glass base, the trunk flare, are basic visuals of how simple a successful planting can be.

6. More soil please.
Again Urban stressed the importance of understanding soils and the surroundings. Soil can be understood as the community of vegetated and urban systems surrounding the planting site. Urban explained the efficiency of his structural cells compared to that of constructed soils (Cu soils). One attendee, an expert and supplier of Cu soils, vehemently disagreed. He argued that the structural rock matrix that makes up the load bearing component of Cu soils do not inversely affect the performance of tree roots as Urban suggested. Not wanting to get into a fight over the success of his inventions, Urban explained, “I’m almost done with the Cu slide…actually, I’ve been done with the Cu slide since 2003.”

7. Harvest stormwater.
“When designing systems it’s important to allow nature to guide us in protecting our natural systems from floatables, hydrocarbons, chemical pollutants, and runoff toxins.” In the green infrastructure overhaul of New York City, large trees will play an important role in the solution and have the ability to “store and process massive amounts of stormwater both in their roots and leaves.”

8. Improve nursery stock.
Nursery stock, in the age of the New York City’s Million Trees Project, have become a hot topic. Tree growth can be determined before a tree is even planted if a basic understanding of the stock is obtained. There are many issues concerning healthy plant growth at nurseries. Proper limbing, pruning, watering, drainage, sunlight, soil volume, and basic organization are all things to consider when visiting a nursery for healthy plants. However, the number one issue is container plants. “We need to stop buying container trees. It’s an unfixable problem!” The girdling of roots has no remedy and their trees have no chance of reaching their potential.

Much of what James Urban discussed in his lecture seems to touch on the ideas of publicity. Yes, the science of tree planting is essential to success but so are “politics.” Urban reiterated this idea by empowering key figures in the crowd.”The Parks Department, the City of New York, and New York Restoration Project need to put pressure on nurseries!” It’s Urban’s hope that New York City will become the benchmark for intelligent street tree planting.

This guest post is by Tyler Silvestro, a master’s degree candidate at the City College of New York (CUNY), and writer for The Architect’s Newspaper.  

Image credit: Silva Cell / Deeproot

Nature and Structure Are One

When we think of paths through nature, we may first think of somewhat muddy trails carved out willy-nilly through the trees, covered in leaves. But a few landscape architects and architects have been showing how paths can be designed, set-apart, yet also enhance the experience of being surrounded by nature while carefully protecting natural habitat.

Reed Hilderbrand, a landscape architecture firm, created a narrow 2,700-foot wooden boardwalk through a previously “unreachable and unknowable” 50-acre wetland near their client’s house in West Stockbridge, Massachusetts. While the path did cut through undisturbed nature, the idea was to create environmentally-sensitive access to improve the stewardship of the unexplored land, 70 percent of which was made up of re-growth forest.


To complement ongoing “woodlot management, edge restoration, and meadow extension” efforts, Reed Hilderbrand proposed a circuit trail that would loop through the wetland. It took nine months working with “conservation biologists, permit specialists, contractors, the property manager, and conservation commissioners to ensure adequate protection of the resource and mitigation of limited construction disturbance.” According to the firm, the only way the team could get permission was if there was a careful evaluation of the “hydrologic and biotic” characteristics of the site, low-impact construction technologies, and design elements that enhanced the wetland. 

“Path alignments were studied in plan from air and then thoroughly tuned on site to navigate among trees and snags, woody thickets, beaver impoundments, significant perennial stream courses, and wildlife corridors,” writes Reed Hilderbrand. Invasive species were removed, to the benefit of local flora and fauna. Overall, the new boardwalk actually supports local habitat: “Since completion, beneficial plant communities including speckled alder and silky dogwood have responded favorably, improving shade cover and food sources. A corresponding increase in wildlife has been observed.”


Another project, Stone River, in eastern New York state, uses stones instead of wooden boardwalks to create a subtle, new way to experience nature. Landscape architect Jon Piasecki, ASLA, Housatonic, writes: “I joined the path itself to the pre-existing stonewall and woods in an attempt to offer the visitor the opportunity to experience a sense of fusion with nature. The goal of this project is to join culture to nature.”

Piasecki, a master with stone, actually moved each stone down the path in a small wood cart and hammered each stone joint into place. “I transferred tens of tons of gravel and sand as a setting bed with a wheelbarrow and I moved nearly 400 tons of stone in the wall and as paving over the 800-foot length of the path. I opened the existing stonewall, chose the course of the path within it and rejoined the residual wall stone in such a way that the path appears to have grown organically within this stonewall where it resides. I was able to personally lay stones so as to avoid individual clumps of ferns, standing trees, fallen logs and existing stones with mossy growths in the wall.”

The silver stone (a mica schist) used in the project is a highly sustainable material because it will last so long. To further cut down on carbon dioxide emissions from the quarrying and cutting process, Piasecki used machines running on vegetable oils. 

The poetry of the landscape is only enhanced by Piasecki’s gentle intervention: “In this instance by joining stone and by making a path into the woods with great sensitivity, I am working to heal, in a small way, the rift between culture and nature that is intrinsic to our modern relationship to the land.”


Lastly, one Japanese architecture firm, Tetsuo Kondo Architects, wound a path through the tree tops in a temporary 3-month project in Tallinn, the capital of Estonia last summer. In the Kadriorg forest, which is located in the center of the city, trees have grown there for three centuries, around a palace built for the Czar of Russia. To provide a startling new look at the trees, a 95-meter-long elevated path was created.  


According to Landezine, the elevated path is made of steel pipe and sheet steel, with no columns touching the forest floor. In places, the paths seem to lean on trees for support (apparently, both the city’s park managers and structural engineers signed-off on this).


The architects write: “Instead of looking up at the trees from the ground, people will be strolling near the leaves, making their way between the branches. A structure made for the forest, a forest that exists for the structure. With no change in the shape of the forest, it will seem that the structure and the forest are one.” 


In these instances, man-made structures complement nature and even enhance the experience of being immersed in nature. These contemporary yet environmentally-sensitive paths help renew these places.

Image credits: (1-3) Half-Mile Hand Built Line: Berkshire Boardwalk, Andrea Jones, Garden Exposures Photo Library, (4-6) Stone River / Jon Piasecki and John Dolan, 2010 (7-9) A Path in the Forest. Reio Avaste / LIFT11

Why Use Ipe When You Can Have Black Locust?


Michael Van Valkenburgh, FASLA, and his fellow speakers got multiple rounds of spontaneous applause at the 2011 ASLA annual meeting for hosting a session on a topic near and dear to many design professionals and wood experts: how to end the unsustainable harvesting of Ipe wood and scale up the use of sustainable alternatives. The real alternative may be Black Locust (Robinia pseudoacacia), which Van Valkenburgh and other progressive landscape architects, architects, engineers, and wood manufacturers have already been using for some time. In addition, domestically-grown Black Locust may offer new opportunities for local sustainable forestry businesses. The trees grow fast and are hardy (in fact, in many areas, they are treated as invasives) and can even take root in urban areas, so they can provide a new source of employment in cities like Cleveland and Detroit, where populations are collapsing and landscapes aren’t as productive as they could be.

Ipe is a tropical hardwood often used in outdoor decks and furniture because it’s so resilient to rain, insects, and weather changes. It’s special properties also mean that it lasts a long time. However, there is a dark side to this wood, which is all too often still used in park and residential projects. Just a few Ipe trees are found per acre in dense, lush tropical forests, which means foresters must wreck havoc on the forest to extract and process those single old trees. Van Valkenburgh and others argue that there must be alternatives.

Why Black Locust?

Stephen Noone, ASLA, senior associate, Michael Van Valkenburgh Associates, said Black Locust lasts just as long as Ipe. He said it’s a “pioneering, not invasive” plant that “takes root on sites that other plants don’t like.” Unlike Ipe, the tree grows together in densely planted areas. In Europe and Asia, it’s already treated as an acceptable crop. In fact, a number of countries are moving forward with planting large groves for wood production, a business that, oddly, has failed to take root in the U.S. 

A research project by Michael Van Valkenburgh Associates’ interns found a plantation in Hungary producing a range of different quality Black Locust woods, including top quality woods. They found that Black Locust can “only be planted in marginal areas where Oak can’t be established.” In a smart move, a local forestry research organization and local wood producers aforested a massive area. Now, 8,500 hectares of dense Black Locust forests are being harvested in just one area there.

Black Locust has “high natural durability, is heavy and hard, but has a tricky kiln drying process,” said Noone. It’s “not going to rot and is insect resistant.” Noone delved into the details of moisture content, and the process needed to achieve the desired content levels. There is a complex multi-step process that involves lettting the freshly cut wood air-dry to reduce moisture and then using a “dehumidifier kiln.” Noone said “the process is very strict,” and “dilligence is required on the part of the drier.” There’s also a long lead time for landscape architects: 40-50 days until the wood can be used. But it’s worth it: Beyond the sustainability benefits, Black Locust is also cost-effective. In bulk, it’s $5.44 per square foot, while Ipe is more than $7 per square foot.

Building a Bridge in Brooklyn

A new pedestrian bridge made entirely of Black Locust and designed to move people from neighborhoods in Brooklyn into Van Valkenburgh’s Brooklyn Bridge Park (see earlier post) is now taking shape. Ted Zolli, HNTB, said in this case, “black locust is better than concrete in terms of its compression, strength, and flexibility” and an “incredibly viable structural material.”


Zolli showed how timber bridges aren’t a new thing. Some 20 percent of current bridges are made up of wood and some are more than 100 years old. This 400-foot long bridge is comprised of pre-fabricated pieces created off-site and the delivered and installed in BK. Some parts of the bridge span 120 feet. All together, there’s about 30 tons of wood. He said for this gangway, Black Locust was the right way to go.

HNTB purposefully tested how vulnerable the wood is to fire and found that it doesn’t lose its strength as it burns. “It’s better than steel and will do better in a fire than the cable wires we are using.” For him and his firm, the real challenge was getting a hold of longer planks and finding the right connector systems for the bridge components.

The Properties of Black Locust

Don Lavender, Landscape Forms, a man Van Valkenburgh called a “national treasure,” discussed the opportunities and challenges in scaling up a domestic Black Locust industry. He said there is great potential for the tree in the U.S. but it’s about “obtaining prime examples and taking selections.” Lavender said the best trees are found in the Appalachian region.

Black Locust was originally given to settlers by the government during the early expansion of the U.S. because it’s very fast growing. Within 15-20 years, the material can be cut down and burned. At 30 years old, it can be used for materials in homes. Lavender said the best of these trees “competed for sunlight with other trees.”

The tree can be used for many products, and even lesser-grade woods aren’t wasted. “100 percent of the tree can be purposefully used.” Lavender said lower grades can be used for mulch, biomass fuel, parquet, and greenhouse poles. The higher grades, #1 grade, premium and premium plus (the top 5 percent), are the result of a more challenging “kiln drying process” that requires “patience.” The wood is tough and resistant to drying for the “same reason it’s so resistant to decay.”

Once dried properly, it can easily be “cut, sawed, drilled, sanded, and shaped.” No outdoor finishes are needed and its screw retention is good. Its Janka hardness also compares favorably with other woods. At 1700, it’s better than Red Oak (1290), but a bit less than tropical hardwoods like Jarrah (1910) and Ipe (3684).  It’s also difficult to glue. But biologically, Black Locust is “remarkably decay resistant.”

Scaling up Cultivation and Production in the U.S.

Van Valkenburgh said the U.S. is falling further and further behind globally. “The country is losing its edge.” Currently, there are 5 million acres of Black Locust under cultivation worldwide, but “virtually zero in the U.S.” Korea has 1.2 million acres, China has another 1 million, while Hungary has 270,000 acres. “This is something that has the potential to be an economic engine in many parts of this country.”

Instead of being viewed as an invasive, as it is in many parts of the U.S., Van Valkenburgh said it should be grown in set-aside areas. Lavender added that the Amish, who “don’t waste anything,” has been using Black Locust for ages. The Amish, who have perfected techniques over generations, are in fact a perfect model for Black Locust production: “proper kiln drying is not something you just get into one day. It takes generations to learn this.” He added that a number of firms have “blundered into kiln drying” and ended up with kindling. “It needs to be done methodically” if an industry is going to bloom here.

Van Valkenburgh is currently using Black Locust imported from Hungary. A firm in Massachusetts is importing containers from Hungary and “taking it upon themselves” to expand the domestic market. While using this wood puts him out of the 500 mile range the Sustainable Sites Initiative (SITES) calls for in sourcing sustainable materials, he said “we have to think bigger about sustainability. The lifespan of these woods is several multiples higher than others.” Still, he wants to see the woods grown domestically. 

The Black Locust market in the U.S. is “still in its infancy” despite the advocacy efforts of Van Valkenburgh and others. Hopefully, some smart city officials will see an opportunity. As one audience member said, Detroit and other cities could not only turn their abandoned lots into forests, but Black Locust forests. Van Valkenburgh went even further: “Planting on reclaimed sites is a great idea.”

Van Valkenburgh, Noone, Zolli, and Lavender kindly shared their 84-page presentation (8MB) full of rich content, photos, and data. Download and help spread the word.

Image credit: (1) ASLA 2006 General Design Honor Award. Small is Beautiful. Michael Van Valkenburgh Associates / Elizabeth Felicella, (2) Walkway into Brooklyn Bridge Park / HNTB