Corten—or weathering steel—is typically used for landscaping and outdoor construction. It is made with alloys that cause its surface to develop a self-protecting rust when exposed to weather. The insulating patina resists corrosion, requires no painting or weather-proofing, and doesn’t compromise structural strength.
Landscape designers appreciate Corten for more than its warm hue. Generally available in sheet and plate form, its strength and durability combined with minimal thickness (typically 3/16 or 1/4 of an inch) allows it to serve in situations where a concrete wall, for instance, would not fit or would visually overwhelm its surroundings. Corten has been used for walls, edgings, dividers, planters, gate trims, and arbors; indeed, its versatility seems to be limited only by the designer’s imagination.
Using Corten in the Garden
To bring more modest Corten accents into your garden, consider the wide range of premade planters, fire pits, benches, and raised-bed boxes widely available online and at retailers.
Using Corten on a larger scale is best turned over to professional designers and contractors, particularly when drainage, weight-bearing, and soil-retention issues are involved. Larger installations are typically manufactured off-site.
Keep in mind the material’s vulnerabilities when choosing where and how to use it: The metal’s corrosion-resistance is not as great in salt air or when placed in constant contact with water. Be prepared to provide special drainage for walls grounded in heavy soil, and keep in mind that runoff from the metal can stain adjacent surfaces, such as concrete.
Dallas landscape architect David Hocker says, “I love steel’s agrarian aesthetic; it’s so reminiscent of miles of steel fencing and pole barns.” In Walnut Creek, California, Joe Huettl raves about a mesmerizing juxtaposition in one of his projects that uses “swaying ‘Karl Foerster’ feather reed grass to backdrop the steady, solid quality of Corten steel walls.” And in London, judges of the renowned RHS Chelsea Flower Show practically drooled over the 2010 The Daily Telegraphgarden installation designed by Andy Sturgeon, which won Best in Show and prominently featured sculptural Corten screens.
The chairman of judges, Michael Balston, was said to call it a clear favorite among the contenders. “There are some that grab you a bit more and Andy’s did for most of us,” Balston told The Guardian at the time. “It has a superb dynamic as you walk around it and different views are revealed.” The Daily Telegraph itself gushed over the use of Corten as a foil for the plantings. “The purples of salvia and aquilegia are the perfect sultry complement to the [steel’s] coppers and bronzes,” wrote garden columnist Stephen Lacey.
Given its no-frills, midcentury industrial flavor, Corten fits most easily into contemporary garden plans. Hocker, for example, relied on weathered steel extensively when he turned an old power station compound into a private city garden. In one section, a low edging of plate steel creates a slightly raised buffalo-grass-covered plinth that sets off an adjacent single mesquite tree like a living sculpture. “Steel has a nice, slim profile without the bulkiness of a concrete wall,” Hocker says. “And in this project, it recalls the site’s industrial past.”