This perennial mix was conceived in 2013 as part of the design of the city square Turbinenplatz in Zurich, and reflects the findings of long-term monitoring of this planting. It was specifically developed for the fluctuating moisture levels found in rain gardens (sunken beds) in locations with approximately 1000 mm of annual precipitation. Inspired by the seasonally wet vegetation of damp meadows and stream banks, it remains structurally stable under heavy rain loads and/or high groundwater tables. From the second year after planting, the meadow-like structure is ideal for forming a dense, water-evaporating tall herbaceous community used in rainwater management and sponge city elements. This perennial mix comprises 27 different species.