Powdery Mildew

Powdery mildew is a fungal disease that affects a wide range of plants. It is one of the easier diseases to spot, as its symptoms are quite distinctive. Infected plants will display white powder-like spots on the leaves and stems. The newer leaves are the most affected, but the mildew can appear on any part of the plant that shows above the ground. As the disease progresses, the spots get larger and thicker as massive numbers of spores form, and the mildew spreads up and down the length of the plant.

Treat with fungicidal sprays or horticultural oil. In cases where the infection is heavy, first remove the diseased parts of the plant and then spray. Preventitave spraying is very effective. Plants such as roses that are prone to mildew can be preventativly sprayed monthly.