The inspiration for SmartSlope Living Retaining Walls came in central Europe, where creator Mark Woolbright marveled at the ways residents found to fit greenery into dense urban dwellings.
“I realize that this type of high population density yields a desire for greenery,” he said. “They really did the maximum with every little space around them. I think that should come to the U.S.”
He saw an opportunity in the vast, often ugly, expanses of retaining walls near buildings, highways and earthworks. And he responded by designing concrete blocks with a cavity for plant roots. The hollow centers let various plants take root and, within months, cover up the wall with natural growth.
He stuck with concrete, even though it carries a hefty carbon footprint, because its structural soundness reassures landscape architects. “[Concrete] is more traditional,” Woolbright said. “Engineers are used to working with it. People see a soundness there.”
But through localized production, Woolbright hopes to limit transportation costs and make the blocks available as widely as possible. His company in St. Louis, working with the Furbish Company of Brooklyn, Md., has the blocks produced at plants in Maryland, Houston, Chicago, and St. Louis. He hopes to find a production partner in the Pacific Northwest next.
The importance of local production is something he learned from an earlier foray into plantable retaining walls at his previous company.
“We wanted to make SmartSlope blocks portably, nimbly, all over the world,” he said. “People were finding the [earlier product] from all over the world, but I couldn’t get the product to them because you can only ship it so far.”

