If the plant has a white powder on the leaf surface, it may be Mildew Fungus. Or a common bacteria, Fire Blight, leaves twigs, branches and especially new growth wilted or blackened.
Dark spots on the upper sides of leaves reveal Black Spot in action. Never on leaf undersides, the spots expand until the leaf is yellow and dotted with black.
For roses, if you see a mosaic pattern of light and dark, or stunted growth this may be signs of a virus called Mosaic Disease.
One of our tree and shrub professionals can help identify problem posers and identify an appropriate treatment plan. From there, we’ll recommend steps to ward off disease before it strikes.