Zoysia japonica is a warm-season turfgrass planted throughout the transition zone of the United States that enters a period of seasonal dormancy as temperatures decline. Growth of the plant is reduced as it enters dormancy (in the fall) and exits dormancy (in the spring). Few studies have examined the morphological and physiological changes undergone by warm-season turfgrasses during this transitional period. Sprigs of Z. japonica were dissected by plant material (root, shoot, and rhizome) and examined under various temperature regimes, both static and directional, and placed under disease pressure from Gaeumannomyces incrustans, Rhizocaotnia solani, and a co-inoculated treatment of the preceding fungi. Disease rating data (severity and incidence), morphological data (length, surface area, average diameter, and total volume), and total nonstructural carbohydrates (TNC) were determined. TNC were further partitioned into free-reducing sugars, starch, sucrose, and total TNC. Results showed significant morphological and physiological changes to root, shoot, and rhizomatous tissue, with results varying between the non-inoculated study and the inoculated study. In the inoculated study, disease severity and incidence measurements were recorded for all inoculated treatments, with incidence and severity greatest overall for the co-inoculated treatment, followed in decreasing incidence/severity by G. incrustans, R. solani, and the noninoculated treatment. Temperature had the most significant effect on results when considered directionally, looking of plants entering or exiting seasonal dormancy.