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American Society of Landscape Architects


March 2005 Issue

The Fleeting and the Steadfast

Two difficult sites in San Francisco. Two prize-winning gardens. One survivor.

By Marty Carlock

The Fleeting and the Steadfast
© Holly Stewart Photography

The view out the south-facing windows of Maria McVarish’s penthouse-style, loft apartment in San Francisco’s Hayes District might have been the square, prosaic roofs of the buildings across the street. Instead, McVarish enjoys a landscape mimicking the rolling hills of northern California. Low undulating planters jammed with close-planted sedums rise, one after another, to a background of yellow ornamental grass, which most days glows with the backlighting of West Coast sun.

This garden with its singular challenges is the work of Andrea Cochran Landscape Architecture in San Francisco. Solving the demands of site and logistics on this and other commissions has worked well for Cochran, who in 2004 won an asla Design Award of Merit for another garden, this one on the steep slopes of the Pacific Heights neighborhood in San Francisco. The Pacific Heights garden—at least in the form that Cochran designed it—no longer exists. However, both commissions had certain problems in common: difficult site access, a need for innovative screening, a desire to do a lot in a small area, and the fact that all site work had to be done by hand. In both, she had to deal with harsh environments—one sunny and overheated, the other steep and shaded.

A 1979 graduate of the Harvard Graduate School of Design, Cochran was born in New York and grew up in New Jersey. She took her GSD diploma to San Francisco for work she thought would be temporary—and never left. “This is the best place to be a landscape architect,” she says. “People here spend more time outside and are into an inside–outside living concept. They’re sophisticated about landscape architecture. They have a personal and economic investment in developing outside space.”

The roof garden was built in 2002 atop a three-story addition to a 1906 warehouse. The add-on was designed by McVarish, an architect, who also rehabbed the four-story warehouse on Ivy Street in the Hayes District. Although McVarish now lives in the loft, the garden was designed in 2002 for a previous occupant.

In addition to the usual problems of site access and screening, Cochran faced on Ivy Street some common rooftop issues: security from an adjoining roof, weight, wind, sun, heat, desiccation, irrigation, and the limitations of the city’s fire codes.

San Francisco’s fire codes strictly limit the number of people who may gather in an area with only one exit, like the roof garden. Consequently, Cochran needed to reduce usable space on the 1,263-square-foot deck. She did so by filling large areas with 16-foot-long planters, then filling strips between the planters with dark, rounded Mexican beach stones that discourage walking. The pedestrian spaces are organized into three assembly areas. Although the remaining area of the deck looks small, it has proven capable of containing 150 people.

Fire codes also dictated some materials choices; no more than 500 square feet of flammable materials was permitted. Cochran used 481 square feet of Trex decking, a plastic lumber product composed of recycled shopping bags and hardwood scraps. The walkable part of the deck intersperses areas of Trex with strips of aluminum checkerplate and square pedestal pavers. To make the aluminum look less industrial and more in harmony with the Trex decking, the metal sheets were cut into strips like planks and screwed down.

Cochran mitigated weight in the planters by using lightweight volcanic soil, which averages 80 pounds per cubic foot. Even so, she limited the height of the planters in the middle of the deck to 18 inches and had them built of lightweight aluminum. Beneath the planting medium is Styrofoam, cut in waves to follow the shape of the planters. “There’s very little soil here,” she says. A layer of fine, pale-colored granite gravel tops the soil, providing both color and mulch.

Bigger planters, taking advantage of better support at the edges of the roof, host bamboo standing in for trees. There’s room for a small table and chairs on the mini-balcony overhanging the street, more chairs under the polycarbonate sunshade, cantilevered over the deck with cables bolted to the brick wall of the warehouse on the west. Spotlights above the awning illuminate it at night. Besides providing security, Cochran’s acrylic screen on the east side hides ugly piping on the adjoining roof.

A sophisticated touch is a bright line drawn across the deck by a strip lighted at night with fiber-optic cable—a feature that draws the eye across the garden from the window to the edge of the balcony.

Pei-Ying Wei, Cochran’s project manager, found herself faced with enormous logistical problems in building the roof garden. To minimize costs, Wei hired a crane to hoist all the materials up in a single day, trying to organize them to arrive in an order they could be used. Despite careful instructions, she found the materials piled in the middle of the deck where support for weight is least trustworthy. The contractor had to be summoned quickly to move it all to the edges. On the other hand, the featherweight aluminum planters, made to Cochran’s specs by a local metal fabricator, were brought up in the elevator.

Budgeted for $150,000, the job came in “closer to $200,000” because of the cost of the polycarbonate screen and sunshade.

Although she used two dozen varieties of succulents, Cochran achieved a unified look by planting five of the six long planters with one variety per planter. The sixth contains a background of Stipa tenuissima, Mexican feather grass. Cochran’s staff did research in a soil lab to determine which succulents grow best in lightweight, lava-rich soil. Most of the plants are from mail order, Cochran says. “The budget required something that wasn’t so rare as to be unusual and pricey.” Exceptions were made for the rare succulents in the four smaller but taller (2 feet square and 3 feet tall) tapered planters on the east edge of the deck.

Despite harsh growing conditions, the garden has needed minimal maintenance. The planters are fitted with built-in, pop-up microsprinklers, whose tiny sprayheads scarcely rise above the low plantings. A local professional gardener tends the roof plantings every two to eight weeks, depending on the season. McVarish says maintenance hasn’t been costly. “We had to replace one bed due to a parasite infection and another because there was a problem with the irrigation system while I was out of town,” she says.

The Ivy Street garden won a Northern California asla Award in 2003.

Project Credits:
Ivy Street Residence designer: Andrea Cochran.
Property owner: Debra Chalsty.
Design/project manager: Pei-Ying Wang.
Building designer, windscreen fabrication consultant: Maria McVarish.
Metal and acrylic fabrication for windscreen and canopy fence: Lawrence La Bianca.
Aluminum planter fabrication: Lewis Metal Fabrications.
Landscape contractor: Pascual Castillo
Structural engineers for windscreen: Endres Ware.
Photographers: Holly Stewart, Jerry Harpur, J. D. Peterson. 

The Short, Glamorous Life of a Show Garden

The Pacific Heights residence had been selected as a “showcase house,” an open-house benefit for the scholarship fund at private University High School in San Francisco. Cochran donated her design services. Why, though, would a designer work for nothing?

Cochran says that these showcase houses and gardens are common fund-raising events. People pay as much as $25 a head to tour houses and gardens by local designers. All the designers, interior and garden, work for free to showcase their talents. They expect to get clients and publicity out of it. And the benefit is always for a good cause, in this case scholarships for students of modest means to one of San Francisco’s better prep schools.

Often, Cochran says, designers shoulder all the costs themselves, just for the publicity, and they go to their contractors and negotiate deals. “Everybody gives something,” she says. In the Pacific Heights case, the clients planned to live there and were willing to put $50,000 into the deck and the garden redesign; even so, Cochran had to ask her contractors to cut their prices. She might not have taken the job if she hadn’t already done work for that client before; she says she knew they would give her the freedom to do something interesting.

Sitting behind a looming four-story house, the 2,579-square-foot yard was connected to the residence only by a stairway from a second-story balcony. The client had four children and wanted the backyard usable as play space. On precipitous Pacific Heights, house lots slope dramatically. In this one, the back of the house stood 10 feet or more above the yard with a steep slope between. “There was no connection between them,” Cochran recalls.

Cochran’s planting choices were restricted by lack of sunlight. Oriented to the north, the yard is in deep shade most of the year. A narrow alleyway accesses the yard, so there was no possibility of bringing in mechanized equipment to move earth, remove spoils, or even deliver materials.

Cochran’s first objective was to knit house and garden together. She suggested a new deck (34 by 14 feet) at the lowest level of the house, extended to overlook the garden, and linked to the bottom of the yard with a broad stairway.

Drawing on her childhood memories of wandering the gravel paths in her grandfather’s garden and inspired by the zig-zag walkway at the Getty Museum in Los Angeles, Cochran created long grass traverses climbing from one side of the yard to the other. Cochran had the Cor-Ten panels, each eight feet long, premeasured, precut, and welded on site into retaining walls 20 to 36 feet long. Cor-Ten also forms the sides and risers for two flights of stairs down from the deck; the steps are filled with spoil and gravel. Her crisp steel barriers, she points out, “create walls without using up space. Cor-Ten makes walls disappear.”

From the existing backyard, the client told Cochran, “The only thing I want to keep is the slide.” Cochran likes to work with willow as screening, so she had her fabricators, The Willow Farm in Pescadero, California, makers of willow furniture, weave a thicket tunnel over the slide. She also planned willow wattle privacy panels for the deck and the first set of stairs. “I wanted to create kind of an Alice in Wonderland fantasy,” she says. The fantasy was established with such imaginative details as large-scale willow balls—2 to 5 feet in diameter—that could be rolled around, willow tepees to house lighting on the deck and in the garden, the willow tunnel over the slide, a literal “lawn chair”—a chair covered with living lawn—and a similar table made from an antique vat planted with grass. The lawn chair and lawn table had to be clipped by hand, but the humor involved seemed worth the effort.

Cochran used willow again, alive this time (Salix caprea ‘Pendula’), to create a visual barrier at the rear of the property. Contractors carried live willow whips through the house, planted them (in a day, Cochran says) in a strip at the property line, and wove the branches gently in and out, tree to tree. Because willow roots are aggressive, they were held in check by root barriers, polyethylene sheeting 60 millimeters thick and 30 inches deep. A drawback of willows is that they are deciduous and not effective screening in winter. “If we could have, we would have had evergreens,” she explains, but the short time factor precluded that.

As punctuation she bound “bolt” columns, aggregations of nonliving willow wands, to hide the steel columns of this fence and a short south fence. For color, Cochran interspersed the willow row with climbing “Sally Holmes” roses that bloom most of the year in San Francisco’s frostless climate. Various species of clematis (C. armandil, ‘Alabast,’ ‘Marie Boissellot,’ ‘Duchess of Edinburgh,’ and ‘Lady Northcliffe’) were placed on the concrete wall on the south side of the garden, forget-me-nots in the planting bed on the north edge and Japanese anemone, digitalis, lady’s mantle (Alchemila mollis) and flowering maple (Abutilon hybrida) in the east beds. “We had to manipulate what was here,” Cochran says, because the lack of good access ruled out bringing in large plants. She moved some camellias to the sides of the yard, left some rhododendrons and large magnolias in place, and sculpted the earth into a stark but functional geometric design.

“Looking down from the deck, you might have thought it was flat,” Cochran says. “But it’s very 3-D when you go down into the garden.” From below, the triangles became angled planes held in place by ascending and descending earth-colored steel. The design from above looked like a graphic, its green zig-zags lining four triangles, two yellow and two green. They were planted with Bacopa, a fast-growing ground cover with foliage in those colors. It also flowers differently: B. ‘Gold’n Pearls’ has yellow flowers, while B. ‘Snowstorm’ has white.

But the industry had other plans for her clients, who soon found themselves moving to New York. They sold the house. As a result, the showpiece garden Cochran created a scant three years ago has been stripped of its fantasy character—its large-scale willow balls are gone, as are its lawn chair, tepees, lanterns, grass-topped table, and tunnel. Cochran’s terraces separated with zig-zag lawn paths remain, although the plantings need tending. Her original all-yellow and all-green triangles apparently have interbred; little yellow is left. The deck and staircase are still in place, but the present owners have removed the wattle panels Cochran installed for privacy vis-à-vis the tall neighboring house. Her living willow screen, planted and interwoven at the extreme northern edge of the property, is doing well, and the owner expects to have it topped this year, a process that should make the remaining branches thicker. Climbing roses interplanted with those willows are flourishing.

One other thing remains: the unsightly but useful children’s slide offering rides from the top to the bottom of the garden.

Was it worth it? The showcase garden did garner Cochran publicity. Besides the national asla Award and a Northern California Chapter Award, this garden has been picked as among a “top 15” by Sunset magazine and has been published in a French and an Italian garden magazine. Cochran says the sponsors of this event call her every year to do another because they got so much press out of it. Still, she’s not sure whether she would put in four more months of work again with the possibility that her design would be ripped out. All gardens change, Cochran points out; designers bear that in mind when they work. But this one changed more suddenly than most.

Boston writer Marty Carlock’s most recent contribution to Landscape Architecture was a profile of artist-consultant Jody Pinto in the October issue.

Project Credits:
Pacific Heights Residence designer: Andrea Cochran.
Design/project manager: Paola Alfani.
Additional installation/ lighting assistance: Paola Alfani, Pei-Ying Wang.
Landscape contractor/metal fabricator: Pascual Castillo.
Willow fabrication: The Willow Farm.
Willow installation: Jerry Doyle.
Deck installation:Paragon General Contractors.
Photographers: Helen Eging, Holly Stewart, Ken Gutmaker.

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