Leaf Spot On Canna

This is an example of leaf spot. This sort of damage can either be bacterial or fungal. Fungal disease are easier to treat but if it’s bacterial there is no cure, just management or replacement with clean stock. Either way, the prudent thing to do is to remove those damaged leaves and throw them away. When you water this plant be sure not to sprinkle the leaves as this promotes both fungal and bacterial leaf diseases. This is always worse in the cool air at night so allow the leaves to dry before nightfall, except of course for rainy weather. Fertilize this plant after you’ve watered it well. Your garden center can recommend a fungicide to protect the newer growth as it develops…if your leaf spot is fungal this will help prevent the spread of the problem.