Meadow-living walls: Creating attractive vertical greenery with meadow seed mixtures – Experiences and recommendations from a three year field trial

Abstract

Living walls (LW) are a way to increase urban green infrastructure. Previous research has mainly focused on microclimatic cooling effect or the technical functioning of LW, while the development of autochthonous plant species and visual plant aspects for LWs have largely been neglected. In this study we focused on the possibility of establishing LWs by seeding, which is not used very often despite obvious advantages such as low costs, low maintenance requirements, and a high species diversity potential.Within a three-year field study in a temperate oceanic climate, we established a meadow-LW by sowing seed mixtures of >30 species on textile mats without soil substrate. After a pre-growing period with horizontal mats in the greenhouse, we placed the greened mats vertically on experimental walls exposed to the North, South, East, and West. We documented species coverage and visibility over time, growth height, and maintenance steps. After cutting, the vegetation recovered within a few weeks and we recommend one complete cut in summer and removing dead plant material after the frost period.From April to October, we observed an increasing growth height and vegetation coverage reaching >100%, followed by a decline till December. Differences of plant species composition and development between different expositions and study years were observed especially after the cold winter of 2017/2018.This study was able to demonstrate that seeded meadow-LWs can be easily established. The use of autochthonous plant species mixtures can create new biodiverse habitats, are aesthetically attractive and increase human wellbeing.