This year’s  Serpentine pavilion by Swiss architect Peter Zumthor opens on Friday, July 1. The first images reveal not just a simple structure of humble materials but also a new type of collaboration for the Serpentine series. Zumthor invited the Dutch planting designer Piet Oudolf to join the project, and although Zumthor retains top billing, his design gives Oudolf center stage. Oudolf recently shared a plan with us of his vibrant garden scheme that forms the heart of the timber-frame structure.

Oudolf’s garden is in the center of the pavilion, whose walls are wrapped with burlap and coated in a grainy black paste. Visitors enter through doorways staggered along a set of exterior and interior walls, moving from the dark, shadowy hallway into a bright, flower-filled atrium that is open to the sky, with Prussian blue benches running around the perimeter and scattered folding chairs and tables designed by Zumthor.

Over 20 varieties of densely packed plantings, from elegant irises to untamed grasses, will grow to various heights, said Oudolf, with some chosen to add “vertical accents” and act as a screen, alternately obscuring and revealing activity on the opposite side of the atrium. And while the blooms will be visually arresting, they will not be overly fragrant. “Scent attracts bees and insects, so we really thought of scent as secondary rather than as a key part of the design. There is scent of course, but it’s just a backdrop to the experience,” said Oudolf, noting that the 1200-square-foot garden should comfortably accommodate 30 to 40 visitors at a time, and that the multiple entrances will ensure easy circulation around the garden bed.

Oudolf said that Zumthor, who received the Serpentine commission last October, contacted him in January while visiting the Netherlands. The two had never worked together, but “He already knew he wanted to do something that created a particular atmosphere, and he had an idea for a kind of closed pavilion with a garden inside,” said Oudolf of Zumthor’s concept for a “hortus conclusus”—a secluded garden within a garden. Julia Peyton-Jones, director of the Serpentine, said the project “brings to mind Zumthor’s Bruder Klaus Chapel in Germany, which he’s called ‘a small space to be quiet,’” while co-director Hans Ulrich Obrist compared the context of the Zumthor-Oudolf collaboration to a Russian matryoschka doll: the pavilion garden sits within the larger grounds of the gallery, which itself is tucked into Kensington Gardens.

Oudolf is best known in the U.S. for his planting design for the Phase I of the High Line in New York, where an unmanicured mix of indigenous grasses and flowers almost appear to grow wild. While the plants differ, Oudolf said that his garden for the Serpentine has a similar “unorganized, spontaneous” effect.

For more details on the opening, check out Daniel Ayat‘s on-site coverage.