Mildew observations from Mildew Valley

Robyn, I live in the powdery mildew capitol of the universe on the foggy coast of California. Depending on the class of your climber, mildew can also be a sign of stress. We find many young own root roses initially have powdery mildew but as they mature and develop better root systems, either PM subsides or resistance improves. It is rarely fatal. Are the plants over- or under-watered? Both can trigger PM in even large, mature garden plants. Also, are you sure your cuttings aren’t trying to go deciduous and lose their leaves, having detected some environmental trigger that it is…winter? Even tiny rooted cuttings can go dormant without dying, and benefit from the fresh foliage when they leaf out again.