Bacteria belonging to the Dickeya genus cause blackleg and soft rot symptoms in many plant hosts, including potato. The dominant story regarding soft rot bacteria like Dickeya is that of plant cell wall degrading enzymes (PCWDEs) being the main drivers of their virulence and pathogenicity. However, there are other cellular and molecular processes playing crucial roles in the disease caused by these pathogens. This dissertation aims to bridge that knowledge gap by increasing our understanding of the interactions between Dickeya and its environment, with the potential of generating knowledge that could translate into effective management options in the future. The first chapter explores how Dickeya senses its environment. Through a combination of computational and experimental methods, this study identified and described a novel potential regulatory mechanism for methyl-accepting chemotaxis proteins in Dickeya dadantii, enriched the available knowledge on this group of proteins, and drew a previously unknown connection between chemotaxis and virulence. The second chapter assessed the genes and molecular mechanisms that make Dickeya “fit” in the different environments it faces when infecting potatoes. This was done by growing randomly barcoded transposon mutant libraries (RB-TnSeq) of Dickeya dadantii and Dickeya dianthicola strains in different in vitro media, in potato stems, and in potato tubers. This study complemented existing knowledge on the genes impacting Dickeya’s growth in vitro and in planta, identifying genes that had not been previously found to be important for fitness. As a whole, the results demonstrate that the potato stems represent a challenging and different environment for Dickeya than other parts of the plants and that each species may have particular strategies for colonization of the stems. Lastly, the third chapter identified and described two new bacterial pathogens of ornamentals, a Pseudomonas amygdali in hibiscus and a Xanthomonas hortorum in oregano. This identification process supported genomic comparisons as a useful and necessary strategy to properly identify bacterial pathogens. The studies that compose this dissertation contribute to the current knowledge on how Dickeya senses and responds to the environment, while also generating useful resources for the study of this and other bacterial plant pathogens.