This thesis explores the role of microbial ecology for landscape architecture. The first chapter contains the theoretical framework of this thesis with an introduction to the world of microorganisms and the state of knowledge in microbial ecology on human health. Afterwards, approaches from the perspective of microbial ecology to promote microbial diversity in an urban context are discussed as well as developments in landscape architecture that overlap with them. Then I formulate my research question based on this scientific framework: Does urban spontaneous vegetation promote microbial activity in the soil and what conclusions can be drawn from this for landscape architectural planning?In the second chapter, I explore Pfeiffer‘s circular chromatography soil test (PCC), an experimental method to visualise the components of a soil sample that also allows conclusions about microbial activity. PCC is not used as a substitute for more complex scientific analysis, but as a visual approach to engage with soil and its biology from a new perspective and with relatively basic resources.The third chapter describes the learning curve during the conduction of the PCC experiments as well as the soil sampling in places with different vegetation during my field trip to Berlin and Munich. The results of the PCC tests are then analysed and interpreted.In the fourth chapter, I discuss the results of the interpretation, addressing findings on microbial activity of the different sampling sites and the suitability of the PCC method for landscape architecture. Finally, I conclude what the results of my literature review and experiments mean for landscape architectural planning and the further research questions that arise from this thesis
