Wednesday, September 29, 2010

Curating the Urban Cemetery as Bird Habitat

Our thanks to landscape designer Aaron Odland for this creative consideration of the habitat potential of urban cemeteries. Images courtesy of Aaron Odland.

When we think about the urban forest, its street trees and parks that often first pop into mind as prime constituents. But there are other institutional land uses that contribute a great deal of square footage to the urban tree canopy. According to the 1994 study "Chicago's Urban Forest Ecosystem: Results of the Chicago Urban Forest Climate Project", 49% of Chicago's 4.1 million trees at the time were on institutional land dominated by vegetation. This category includes parks, forest preserves, golf courses, and cemeteries. This study also found that the tree composition throughout Chicago was dominated by the pioneer species green ash (12.9%) and cottonwood (15.8%). While any type of tree canopy might contribute to the infrastructure tree benefits of stormwater retention, air pollution removal, energy reduction, etc. it's habitat value that really suffers from a as a lack of diversity of tree types and sizes. So, if one is going to improve urban forest structural composition, what better place to start than these institutional lands dominated by vegetation? And cemeteries, I think, are one of the most overlooked sources of potential urban habitat.


Chicago is home to numerous historic cemeteries, such as Graceland Cemetery (burial place for Daniel H. Burnham, Louis Sullivan, George Pullman, etc.) and Rosehill Cemetery (final resting place for Charles M. Schwab, Richard Warren Sears, Oscar Mayer, etc.). Rosehill is the largest cemetery in Chicago, covering 350 acres, but there are some more modest burial grounds in the city, such as St. Boniface in the Uptown neighborhood, which is about 34 acres. Considering that the average residential block size in Chicago is about 5 acres, this smaller cemetery is still an impressively large piece of real estate in a dense urban area. To cobble together such a contiguous piece of land today in any major city would be virtually impossible. Such parcels exist only because of their historic use.

Using the "L" train line as and its stops as a reference point, if you look out 1/4 mile radius from the train stations in the Uptown neighborhood, there is not a great deal of park land evident. And that which does exist cannot compare in size to St. Boniface Cemetery. The surrounding buildings tend to be multi-story residential or mixed use, and the surrounding streets don't all have street trees or much vegetation at all. So the green space provided by the cemetery is important to the neighborhood and its habitat potential.

Edge Condition at St. Boniface Cemetery
Main Drive at St. Boniface
Rabbit at St. Boniface
There are quite a few mature trees in St. Boniface Cemetery, and in the midst of it you can feel quite separated from the hustle and bustle of the city. I saw a rabbit peeking out of a shrub during my visit there, and friends who live nearby have told me of seeing foxes. There also are peregrine falcons nesting on the adjacent Uptown Theater for the last ten years, which I would think must have some relation to the proximity of this large green space.

Cemeteries are, or course, primarily a place for burial and remembrance of the dead. So, habitat for flora and fauna must be a secondary concern. In an ideal situation, once could guide the cemetery's vegetation to represent a mix of grassland, shrubs, understory trees and larger shade trees that would provide a diverse range of habitat for wildlife. But, the current aesthetic of American burial spaces is deeply rooted in the English pastoral landscape tradition with large swathes of green lawn with patches of trees. Perhaps it is that trees in manicured, mowed turf provide an orderly landscape that suggests man in control of nature. Regardless, the question becomes how to respect this aesthetic that people expect for burial of their loved ones while still improving the habitat value of the cemeteries. If we remove the horizontal plane from design consideration and assume it to be turf grass, this still leaves the vertical plane to manipulate. This vertical realm is perhaps best suited for improving bird habitat.

A mix of tree levels is very advantageous to a broad range of species as not all birds like the same food, nesting conditions, etc. According to an Ohio Department of Natural Resources article Song Birds in the Urban Forest? Trees Make It Possible, "the top tier of tall-growing hardwood species like maple, hickory, oak and elm is the nesting ground to Baltimore Orioles, Red-Eyed Vireos, and Scarlet Tanagers. The acorns and nuts from these trees also provide food for various species. Nuthatches prefer tall evergreens for nesting, and many birds may eat the sap, seeds and needles of these trees that also provide shelter from weather and predators. Mid-tier trees such as mulberry, redbud, plum, etc. provide a variety of food and also nesting places for species such as Wood Thrushes. Moving down, lower tier hollies and shrubby dogwoods attract many birds, such as Cardinals and Gray Catbirds. Finally at the ground level, having open habitat encourages specific species like the American Robin and Bluebird." Cemeteries already have that final condition available, which is a good start.

Birdhouse at Woodland Cemetery in Stockholm, Sweden
So what is the incentive for cemeteries to increase their tree diversity to improve wildlife habitat? Perhaps city programs targeting sustainability could be funding sources, but I think there might also be private revenue streams to tap into, especially in the case of habitat improvements that will attract more birds. According to a 2006 US Fish and Wildlife Service report, there were 48 million birders in the US, which was 21% of the US population at the time of the survey. They define "birder" as someone who makes a trip 1+ mile from their home to look at birds (excluding zoo visits) and/or tries specifically to identify birds around their home. The trip-related and equipment-related expenditures associated with birding in 2006 generated over $82 billion in total industry output. So, it's big recreational business, and at a time when cemeteries are struggling to find new revenue sources for their upkeep and maintenance, a bit of this money could be a boon.

How could cemeteries attract birders? Many historic cemeteries, such as Chicago's Graceland Cemetery, offer tours. For example, The Chicago Architectural Foundation has $15 tours on Sundays from August through October. Why not have a bird watching tour sponsored by a group that shares some of the income with the facility? The tour could even highlight the habitat work through the tree plantings and solicit donations for continued improvements. This is just one idea, but I'm certain that in some capacity, if you build the bird habitat, the birders will find it, as they do carry binoculars.

More on the habitat value of cemeteries:
Aaron Odland is a landscape designer for Ten Eyck Landscape Architects in Austin, TX. Odland received his Master of Landscape Architecture from UC Berkeley. His appreciation for quiet spaces and Chas Addams comics has fostered his interest in cemeteries.

Tuesday, September 28, 2010

New Bowery Cemetery of the Spanish and Portuguese Synagogue


A sliver of land filled with conifers and surrounded by a low blue wall and lovely wrought iron caught our attention during a recent walk along West 11th Street. This triangular parcel is the New Bowery Cemetery of the Spanish and Portuguese Synagogue, one of three cemeteries of the Congregation Shearith Israel.


According to the Cemeteries of Congregation Shearith Israel website, the cemetery was a large, square plot when burials began in 1805. The cemetery was reduced in size in 1830 with the construction of West 11th Street.  Grave sites affected by the new street layout were moved to a Shearith Israel cemetery at 98-110 West 21st Street.

In 1847, the Rural Cemetery Act legislated the establishment of cemeteries in rural areas of New York State such as western Queens.  Thus, when the Common Council of New York City banned new burials within Manhattan (the only borough of NYC at the time), subsequent interments of Shearith Israel congregants were made in Queens. 


Stay tuned for an essay about Urban Cemetery as Arboretum by landscape designer Aaron Odland.

Monday, September 27, 2010

London planetree walls off decay


Did you know that trees can build walls?  In fact, trees respond to bacterial, fungal, and other attacks by constructing four walls, first modeled by Dr. Alex Shigo and named CODIT or compartmentalization of decay in trees.

CODIT via "Tree Decay" -- Figure 15 (image source)
The first wall is formed by plugged xylem cells which prevents the vertical spread of decay while late-forming cells are plugged to create the second wall which resists the inward spread of decay.  The third wall, formed by ray cells, prevents the radial spread of decay.  Together, these three walls are known as the reaction zone.  The fourth wall, also known as the barrier zone, inhibits the outward spread of decay.  This wall is "an anatomical and a chemical wall" formed by the cambium. 


CODIT pattern via "Tree Decay" -- Figure 41 (image source)
Review more patterns of compartmentalization here.

The photographs used in this post are of a London planetree round shown during the first meeting of the Trees New York Citizen Pruner Fall 2010 course being taught by Steven Boyce of the Friends of Greenwich Street.  Stay tuned for our presentation of Boyce's paper titled "It Takes a Stewardship Village: Reducing Street Tree Mortality Rates in an NYC Neighborhood."

Citations:
  • Tree Decay: An Expanded Concept, USDA Forest Service Information Bulletin Number 419, April 1979 (online)
  • ISA Arborists' Certification Guide, Sharon J. Lilly, 2001

Wednesday, September 22, 2010

Sukkah City in Union Square Park


A dozen sukkahs were on display on September 19 and 20 in Union Square Park. 600 designers entered the Sukkah City international design competition.  12 finalists were selected. 



We went to the Sukkah City village on the first day.  One of the sukkahs, Shim Sukkah by Tinder, Tinker of Sagle, Idaho was still being constructed; it is our favorite.  The designers used unassuming wooden shims to create an intricate and beautiful structure. 
 
A sukkah, quoting the Sukkah City poster, is
Biblical in origin...an ephemeral, elemental shelter, erected for one week each fall, in which it is customary to share meals, entertain, sleep, and rejoice....the sukkah's religious function is to commemorate the temporary structures that the Israelites dwelled in during their exodus form Egypt....The Sukkah is a means of ceremonially practicing homelessness....

Ronald Rael and Virginia San Fratello's Sukkah of the Signs is a literal interpretation of "practicing homelessness." Sukkah of the Signs is "clad with cardboard signs purchased from destitute individuals across the U.S."  (Proceeds from the Sukkah City auction will benefit Housing Works.)  Most viewers of this sukkah spent several minutes reading the signs on the sukkah's exterior.

There are specific rules for constructing a sukkah.  Again, quoting the exhibit's poster:
The structure must be temporary, have at least two and a half walls, be big enough to contain a table, and have a roof made of shade-providing organic materials through which one can see the stars.
The guidelines do not provide a maximum area, but the New York Department of Buildings does not consider a structure larger than 19 feet x 8 feet to be temporary.  More construction details can be found here


Children at the exhibit enjoyed sukkahs that provided climbing and lounging features such as Star Cocoon by Volkna Alkanoglu of Los Angeles and In Tension by SO-IL of Brooklyn.  The interior space of the latter was quite limited but the space was large enough to hold a short-log table and chairs.


Two sukkahs incorporated herbaceous flowers.  Flowers hung from the ceiling of In Tension and Single Thread by Matter Practice of Brooklyn.


Based on viewers's reactions, the most impressive sukkah was Log by Kyle May and Scott Abrahams of Manhattan.  Unlike the other 11 sukkahs, access to this sukkah was limited to the designers and to a rabbi. We overheard one woman say to another:
Nothing hits the ground.  Everything is suspended from the log.  It's incredible!

However, our second favorite, Fractured Bubble by Henry Grossman and Babak Bryan of Long Island City, won New York magazine's People's Choice contest and will be displayed in Union Square until October 2.  We like Fractured Bubble for its creative use of a declared invasive plant. The roof of this sukkah is composed of the perennial grass, Phragmites australis or common reed, which the designers harvested from Corona Park in Queens.  New York City Department of Parks & Recreation lists phragmites as "one of the 20 most invasive plants" in the state!  Read more about the grass here.


You can see selected sukkahs at the Center for Architecture on La Guardia Place from September 22 to October 30.

Monday, September 20, 2010

urbancanvas Design Competition, or beautifying temporary protective structures

Urban Umbrella urbanSHED
In February, we reported about the urbanSHED International Design Competition on exhibit at the AIANYC Gallery on La Guardia Place. Three proposals were selected as finalists: Tripod MOD(ule) (XChange Architects with Ex Nihilo Studio, Rider Levett Bucknall, and Weidlinger Associates), urbanCLOUD (KNEstudio with Arup), and Urban Umbrella (Young Hwan Choi, University of Pennsylvania student, with Agencie Group). urbanSHED was sponsored by several local institutions including three City agencies: Department of Buildings, Department of City Planning, and Department of Transportation.

Green Screen urbancanvas design via nyc.gov (source)
In June, the Department of Buildings and the Department of Cultural Affairs with support from The Rockefeller Foundation announced the urbancanvas Design Competition. Urbancanvas goes beyond urbanSHED in the number of structures it aims to beautify. Four (construction fences, sidewalk sheds, supported scaffolds, and cocoons) instead of one (sidewalk sheds).

There are eight finalists and you can vote for your favorite design starting today until October 1, 2010 5:00PM (EST). The four designs with the highest number of votes will be available to building owners with temporary protective structures located on or over City-owned property via the urbancanvas Pilot Program.  The City has developed a How and When to Use Artwork at Construction Sites guide for building owners.

Don't forget to vote!

[Hat tip: WSJ Metropolis]

Dominique Browning's new garden book recommendations


Readers of House & Garden will recognize Dominique Browning as the editor-in-chief of the now defunct magazine.  Browning has authored six books including her newest, titled Slow Love. I miss House & Garden and Browning's editorials but a local bookseller, McNally Jackson, is providing some Browning love.  The bookshop has created a display of seven garden books recommended by the author:
  1. Gardening for a Lifetime
  2. Garden Guide New York City
  3. Edible Estates 
  4. Talking Dirt
  5. vegetables, herbs & fruit
  6. The Seasons of Henry's Farm
  7. The Locavore's Handbook.
Here is our list of new garden/food books:
  • The Green Roof Manual: A Professional Guide to Design, Installation, and Maintenance (Edmund C. Snodgrass and Linda McIntyre)
  • Grocery Gardening: Planting, Preparing and Preserving Fresh Food (Jean Ann Van Krevelen)
  • In the Kitchen with A Good Appetite: 150 Recipes and Stories About the Food You Love (Melissa Clark)
  • Kitchen Literacy: How We Lost Knowledge of Where Food Comes from and Why We Need to Get It Back (Ann Vileisis)
  • Farm City: The Education of an Urban Farmer (Novella Carpenter)
  • Above the Pavement—the Farm! Architecture & Agriculture at PF1 (Amale Andraos and Dan Wood)
  • update, September 21, 2010: Today we learned about a forthcoming book, Asphalt to Ecosystems: Design Ideas for Schoolyard Transformation, by Sharon Gamson Danks, an environmental planner and founding partner of Bay Tree Design, Inc. in Berkeley, California.  In Asphalt to Ecosystems, Dank "showcase[s] some of the world's most innovative green schoolyards" including edible gardens.  
Don't forget to check out our Printed Leaf Bookshop via Amazon.

Friday, September 17, 2010

Don't have a seat

Fire hydrants on Broadway

Revolution at New York's storm drains

Given yesterday's severe storm in the New York, we thought we would repost about the Curbolution entry to the Minds in the Gutter exhibit.  The original essay was published on September 13.




The cleverly named runoff solution - Curbolution - was submitted by Team Sang-ayuna to the 2010 Minds in the Gutter "sidewalk as an opportunity for stormwater management" exhibit.  Team Sang-ayuna was composed of Cornell students Gregory Falco ('10), David Afable ('12), and Christian Paunon ('12).  Falco, Afable, and Paunon are from the New York City area.  Experience with combined sewer overflows -- clogged streets with "nasty stuff laying around" -- inspired the young men, plus their interest in sustainable design.



Falco, in an interview with local ecologist, described his team's approach as the "best solution for the urban environment" in contrast to conventional typologies such as a wetland or a bioswale.  In fact, Curbolution is a modified bioswale.  Falco admitted that there is not one solution to stormwater run-off but noted that his team's design was efficient because it utilizes the existing landscape.  Of the projects included in the Minds in the Gutter exhibit, Curbolution lies at one end of two scales: size (it is a small-scale intervention) and investment (it is a retrofit). 



Stay tuned for more posts about Mind in the Gutter entries.  We will consider proposals by Robin Key Landscape Architecture (Minetta Creek Revisited); Brooklyn Greenroof; and NYC Parks (Greenstreets) in advance of an exhibit at URBAN GREEN EXPO 2010, September 29-30, 2010.

Thursday, September 16, 2010

Bustling Jefferson Market to passive Garden

Jefferson Market Garden, Greenacre Park, The Conservatory Garden (Central Park), and The Heather Garden (Fort Tryon Park) are "tucked-away gems," wrote Jeryl Brunner in the September 2010 issue of Delta's Sky magazine.  Jefferson Market Garden borders the very busy Sixth Avenue aka Avenue of the Americas, but the garden is easy to overlook for two main reasons.  One, the garden does not have an entrance on Sixth Avenue.  Its entrance is on Greenwich Street.  Two, the garden's Sixth Avenue fence is covered in vines and climbing roses partially obscuring views into the space.

Before there was the Jefferson Market Garden there was the Jefferson Country Market founded in 1833, then the Womens House of Detention built in 1927, and finally in 1974, the land was transferred to NYC Parks and has since been stewarded by the Jefferson Market Garden Committee, Inc.  (The standing 1877 courthouse is now a public library.)  The garden was designed "in the spirit of Frederick Law Olmsted" by landscape designer Pamela Berdan.


On a recent visit on a sunny Saturday afternoon, there were many visitors including friends of the volunteers staffing the entrance, strollers, sightseers, loungers, an amorous couple, and a pair of women seeking gardening inspiration.


My favorite parts of the garden were the white blooms of oakleaf hydrangeas and mallows, small greenhouse, the babbling fish pond, and two large Kentucky yellowwood (Cladrastis kentukea) trees growing in the central lawn.  (The former Latin name was Cladrastis lutea.)  The garden's website describes the trees as "rare."  The yellowwood's habitat can be found in "relatively small portions of the southeastern United States" and the trees are "scattered and not common throughout [their] range," according to the University of Connecticut's Plants Database.  Yellowwood was named for the color of its heartwood - yellow - and was used in the dye industry.  I missed the spring bloom of "perfect white and very fragrant" flowers, but will visit the garden again in the fall to see the trees leguminous fruit pods.  Yellowwood is in the Fabaceae (Leguminosae) or pea (legume) family.

Wednesday, September 15, 2010

An orchard grew in Brooklyn Heights?


When we came across several fruit-named streets in Brooklyn Heights, I immediately thought that the area was historically an orchard.  I was wrong.  It would have been challenging to maintain a tropical fruit orchard in New York.  And where would a cranberry bog fit into the landscape? Read about creating a bog garden on the Brooklyn Botanic Garden website.  Also, note the cross street -- Willow Street. 

The Brooklyn Heights's streets Orange, Cranberry, and Pineapple were originally named for aristocratic families, a practice that nineteenth century resident Lady Middagh found "pretentious," so she renamed the streets.  These streets influenced the name of a nearby sitting area -- the Fruit Street Sitting Area.


In researching for our post about parks in the movies, I learned that Cher's character in Moonstruck lived in a house on Cranberry Street.  Cinematic Parks found this amusing as Cher's character was from a working class family and that house on Cranberry Street was marketed for $5 million!

Tuesday, September 14, 2010

Reel affairs with New York City parks

Gramercy Park image via Wiki Commons author Dmadeo
Watching Woody Allen's "Manhattan Murder Mystery" recently, I recognized Gramercy Park and Stuyvesant Square!  A quick search of the internet confirmed my guesses.  More recently, the Bowery Boys wrote about the World Trade Center in movies which convinced me to write a post about the city's parks in movies.  Another internet search revealed a NYC Parks webpage - Cinematic Parks - which lists films that feature city parks.

As you might expect, Central Park has been featured in many well-known films such as Love Story (1970), Annie Hall (1977), Kramer vs. Kramer (1979), Tootsie (1983), and Hannah and Her Sisters (1986) and the park has been the subject of movies including Central Park (1932).


Scenes of Washington Square Park  can be seen in When Harry Met Sally (1989) and Kids (1995).  The park's chess playing area - a "battleground for chess enthusiasts" - was famously portrayed in Searching for Bobby Fischer (1993) while Will Smith's I Am Legend (2007) character lived in a townhouse off the park.

The Cinematic Parks webpage also notes that parks have "stood in" for each other.  For example, the Bleecker Street sitting area (I think it is Father Demo Square) represented a park in Brooklyn Heights.  The movie was Moonstruck (1987) starring Cher whose character lived on Cranberry Street (see tomorrow's post).

Prospect Park image via Flick author nydiscovery
Parks from other New York boroughs have been featured in films, too!  Frederick Law Olmsted's other New York pastoral masterpiece, Prospect Park, can be seen in Sophie's Choice (1982) and As Good As It Gets (1997).  The Bronx's New York Botanical Gardens Enid A. Haupt Conservatory was the backdrop for an "important scene" in The Age of Innocence (1993). 

Finally, the "borough of parks" aka Staten Island has hosted film crews for Little Children (Walker Park), Margot at the Wedding (Conference House Park), and American Gangster (South Beach and the Cromwell Recreation Center).

Monday, September 13, 2010

Stormwater management revolution at the curb

We would like to thank Gregory Falco for his interview with local ecologist in May 2010. All images courtesy of Gregory Falco.



The cleverly named runoff solution - Curbolution - was submitted by Team Sang-ayuna to the 2010 Minds in the Gutter "sidewalk as an opportunity for stormwater management" exhibit.  Team Sang-ayuna was composed of Cornell students Gregory Falco ('10), David Afable ('12), and Christian Paunon ('12).  Falco, Afable, and Paunon are from the New York City area.  Experience with combined sewer overflows -- clogged streets with "nasty stuff laying around" -- inspired the young men, plus their interest in sustainable design.



Falco, in an interview with local ecologist, described his team's approach as the "best solution for the urban environment" in contrast to conventional typologies such as a wetland or a bioswale.  In fact, Curbolution is a modified bioswale.  Falco admitted that there is not one solution to stormwater run-off but noted that his team's design was efficient because it utilizes the existing landscape.  Of the projects included in the Minds in the Gutter exhibit, Curbolution lies at one end of two scales: size (it is a small-scale intervention) and investment (it is a retrofit). 



Stay tuned for more posts about Mind in the Gutter entries.  We will consider proposals by Robin Key Landscape Architecture (Minetta Creek Revisited); Brooklyn Greenroof; and NYC Parks (Greenstreets) in advance of an exhibit at URBAN GREEN EXPO 2010, September 29-30, 2010.

Friday, September 10, 2010

Even books can be delivered in New York

McNally Jackson Books offers free local delivery of books by bicycle within the following zone: north of Canal Street, south of 8th Street, east of Hudson Street, and west of Avenue B.

Wednesday, September 8, 2010

Floral retail

If you were expecting photographs of flower shops, stay tuned for a write-up of local florists. In the meantime, these nodding potted flowers decorated Fred Perry's SoHo boutique in August.

Flower power in the Montreal Metro

Well, not exactly.  Montreal's Metro is not florally-powered but the system has been 100% powered by electricity since 1966.

Monday, September 6, 2010

A hectare of urban trees is worthwhile for birds

Black throated blue warbler.  Source: Wiki Commons / mdf

Landscape ecologists Stephen Matthews and Paul Rodewald of the Ohio State University found that even a small patch of urban trees, like a hectare-large arboretum, provides valuable stopover habitat for migratory birds, though the authors noted that larger, contiguous patches of tree cover are better.  Read more at the BBC News Science & Environment website.

[Hat tip: The Metropolitan Field Guide]

Wednesday, September 1, 2010

Green-It-Yourself roof garden at 594 Broadway

You've heard of do-it-yourself, or DIY.  Designers Atom Cianfarani and Lori Gibbs of Green Roof Workshop have coined the phrase Green-It-Yourself to describe their affordable and accessible approach to green roof design-build.

I attended the last day of a two-week extensive* green roof garden installation at 594 Broadway, a Newmark Knight Frank building in SoHo (Project 594 Roof Garden), the home of the project organizer, Flavorpill.com. The work that had occurred prior to my attendance included the installation of a polyethylene root guard (Atom recommended using another product, EPDM); a recycled Geo-Textile, USA-made roof protection mat; recycled wood perimeter; an Optigreen drainage layer (resembles egg crates); a recycled Geo-Textile, USA-made drain/filter cloth; wood chips at the perimeter, and GaiaSoil enclosed in burlap sacks.

On the final day of the project, two types of compost were laid down -- one for the sedums and one for cuttings and seeds. In addition, the seed areas received a layer of 1:1:1/2 clean sand, compost, and lava rock; the cuttings areas received a layer of lava rock; and the sedum areas were lightly topped with wood chips. This system, as described by Atom, is a "German system using accessible materials." Only two of the materials -- the drainage layer and roof barrier -- used in the 594 Broadway roof garden are difficult to source outside the internet or a local hardware store and Atom offers these two products through Green It Yourself Supply shop.

Despite wearing gloves, I got my hands dirty which was great!  I laid down compost and wood chips as well as arranged sedums in a three per square foot pattern and planted a few of them.  The plant palette included Sedum album (white stonecrop), S. acre (goldmoss stonecrop), S. spurium (tworow stonecrop), S. sexangulare (tasteless stonecrop), and Sempervivum tectorum (hens and chicks).   (See PLANTS Profile for Sedum for more information.)  Ice plant was also planted.  I was surprised by the inclusion of ice plant because it is considered invasive in California (see USDA PLANTS Weeds of California for more information).  I do not know the species information for the ice plant used at 594 Broadway.

A green roof typically costs $30-50 per square foot compared to $2.70 per square foot at 594 Broadway. A brownstone in Brooklyn served as a template for this significant cost reduction.  Atom believes that there will be "green roofs all over New York City if [the system] is affordable" which is why she advocates for accessible and affordable materials, not proprietary systems.

The Project 594 Roof Garden was envisioned to reduce the building's contribution to stormwater run-off and to reduce cooling costs.  Green roofs are one of the best management practices encouraged by the City as part of its PlaNYC 2030 Water Quality Initiative.  The monetary incentive for green roof installation is "a property tax abatement to off-set 35% of the installation cost of a green roof" (also see DDC Cool & Green Roofing Manual).

Finally, on a sociological note, most of the volunteers (excluding Atom, Natasha, and two official women videographers) were women (14 of 18). 

Thank you to Natasha at Flavorpill and to KIND bars, Tumeric Alive, and Beyond Kombucha for the refreshments -- it was hot on the roof!

* An extensive roof is light weight and shallow in contrast to an intensive roof which is heavy weight and deep.  The roof at 594 Broadway has two inches of growing medium ad weighs 10-11 lbs/square foot at saturation.