Don’t be fooled by trick phenology. Today Cincinnati hit 508 growing degree days as measured at CVG. This is well ahead of what is shown on the OSU phenology website because that uses weather data from Piketon, Ohio. Hardly representative! One would expect black locust trees to be approaching full bloom at 508 degree days and, indeed, they are at my location. Black locust is the indicator plant for adult Emerald Ash Borer emergence.