Putting conservation gardening into practice

Abstract Conservation gardening (CG) is the widespread planting of urban green spaces with declining native plant species and the transformation of the gardening industry into a socio-ecological conservation tool. However, information on which plants are amenable, what conditions they require, and where they can be purchased remains scarce and not readily available. Using Germany as an example, we demonstrate a workflow that synthesizes such data. We synthesized the Red Lists of all 16 federal states in Germany, and text-mined a comprehensive platform for garden plants, as well as multiple German producers of native plants. We summarize all available data via a user-friendly app (https://conservation-gardening.shinyapps.io/app-en/), allowing gardeners to retrieve region-specific lists of CG plants, as well as corresponding planting and purchasing advice. We found that a median of 845 plant species are red-listed across federal states (ranging from 515 to 1,123), with a median of 41% of species amenable to CG (ranging from 29–53%), totalling in 988 CG species. 650 (66%) of these are already available for purchase. We found that many CG plants are drought-tolerant and require less fertilizer on average, with implications for long-term urban planning and climate adaptation. Together with gardening experts, we present purchasable CG balcony plants for each federal state, highlighting that CG can happen now and also for people without gardens. Our analysis suggests plant extinction risk could potentially be reduced by a median of 29% across Germany if CG were widely implemented. Our study highlights a considerable potential for CG to initiate transformative change to help bend the curve of biodiversity loss.