Using ecological knowledge for landscaping with plants in cities

To date, urban plant selection has mainly been focused on species-level characteristics such as aesthetics and suitability to form assemblages. In natural environments, however, plant species form natural assemblages based on positive (and negative) ecological interactions. Implementing an assemblage-level approach to plant selection in an urban context that utilises ecological interactions between species can not only look aesthetically pleasing but can also reduce common maintenance issues and improve plant performance and resilience. Agricultural practice has long since recognised the usefulness of utilising species interactions to improve plant and soil health, deter pests and increase resource use and diversity. However, the benefits of assemblage-level interactions have seldom been translated into the urban context. In this opinion piece, we advocate for the use of an assemblage-level approach for species selection in urban settings that draws on the interaction between species, based on key ecological principles. We suggest five such principles; facilitation, competition and niche separation, enemy avoidance and deterrence, plant-soil interactions and species diversity. We propose selected examples of how they have been utilised in agriculture and argue that these concepts can be adopted in urban landscapes.