The Big One: Keepin’ it clean

Company: Pacific Landscape Management
Location: Portland, Ore.

Access to several rooftop and patio gardens makes for a challenging worksite at the Oregon Health & Science University (OHSU) South Waterfront campus.

According to Adam Flint, branch manager for Pacific Landscape Management, crews must walk through the hospital on their way to maintain landscapes.

“The expectations of OHSU, from a cleanliness standpoint, is completely different from any of the other green roofs we manage,” says Flint. “We have to be sharp and professional as we’re walking through the building with all of the material they’ve generated throughout the day.”

Some gardens, he adds, are only accessible through windows, meaning crews have to navigate the functioning hospital to access their workspaces.

Irrigating rooftop patios adds another layer of complexity to the project, according to Justin Lenhardt, branch manager with PLM. To ensure no water leaks from irrigation into the hospital space, crews closely manage the site’s drip irrigation system and utilize rainwater as often as possible.

“There’s definitely a fine line there trying to use the resource appropriately and keep the landscape beautiful,” he adds.

Pacific Landscape Management won a Gold Award from the National Association of Landscape Professionals’ Awards of Excellence program for this project.

(Photo courtesy of Pacific Landscape Management)

A ground-level view of the fourth-floor gardens showcases the varying landscapes crews must work in.

(Photo courtesy of Pacific Landscape Management)

Water filtration plays a crucial part in Pacific Landscape Management’s design of rooftop gardens.

(Photo courtesy of Pacific Landscape Management)

A view of the same patio garden shows a children’s play area amid sedum groundcover and other native plantings.

(Photo courtesy of Pacific Landscape Management)

The client wanted this project to provide scenic views of the city and the surrounding landscapes.

(Photo courtesy of Pacific Landscape Management)

One of the several rooftop gardens on the campus. Pacific Landscape Management utilized many permeable surfaces to aid in drainage and rainwater collection.

(Photo courtesy of Pacific Landscape Management)

A lush rooftop sitting garden that faces north to capture the views of the downtown cityscape. Trees in large, raised planters provide shade and contribute to a diversity of maintenance services required, including arbor care and broadleaf weed control.

(Photo courtesy of Pacific Landscape Management)

A view of the rain garden collection at ground level. Drip irrigation supplements off-season rainwater.

(Photo courtesy of Pacific Landscape Management)

Groundcover density and variety of plant materials offer an oasis for occupants throughout the working day. Effective irrigation is key to maintenance success 100 feet from ground level.