See:
Cherry (Prunus spp.) - Verticillium Wilt
Note Out of a dozen samples there was only one diagnosed with Verticillium wilt by the OSU Plant Clinic. Verticillium wilt is a serious disease of many economically important agricultural and horticultural crops. The disease affects herbaceous annuals and perennials as well as woody trees and shrubs. Microsclerotia are aggregations of thick-walled, darkly pigmented cells, which can remain dormant and survive in soils for 10 years or more. The fungus colonizes roots and enters the xylem of susceptible hosts, where it grows, sporulates, and eventually disrupts water transport. Plants affected by Verticillium wilt can exhibit chlorosis, wilting, defoliation, and premature senescence. Maintaining adequate, but not excessive, moisture and nitrogen levels can help alleviate symptoms but curative measures do not exist. Control tactics should be aimed at preventing disease.