Frank Brines, ARS RosarianSpecial to Valley NewsThe weather has moderated slightly, and along with the change comes cooler nights. Fall brings warm days and cool nights, conditions that can ensure large colorful blossoms. But those same conditions also bring moisture and a daily accumulation of ash and small dust particles. These create a great environment for fungal diseases. One example is powdery mildew. Early on, it shows slight purple splotches on the underside of leaves and white powdery spots on top and white powder on the peduncle or neck of the rose blossom.Another common fungal disease is black spot. It is marked by black spots with fuzzy edges, before turning yellow and brown. Often it does not kill the plant outright but, over time, the loss of leaves can weaken the
