Bacterial Leaf Spot

Bacterial leaf spot can be identified by irregular-shaped black/brown spots on leaves; often surrounded by a yellow halo. When the disease affects leaf edges, these areas will become papery and take on a light brown color.

It is highly recommended to try physical prevention/control methods before resorting to chemical control. If you choose to use a bactericide, select a product that is labelled for bacterial leaf spot and rotate products where possible to minimize resistance. Not all bactericide products work on all types of bacterial diseases. Check local regulations (or your local Extension Office where applicable) to identify products that can be used in home gardens in your area. Follow label instructions carefully for safe and effective bactericide application and to ensure that edible crops are safe to harvest. Test bactericide on a few plants before widespread application. Spray bactericide in the late evening and try to avoid spraying during blooming to minimize negative impacts on pollinators- some bactericides are directly lethal to pollinators, and others can have indirect negative impacts. Bactericide may not help if the plant is already severely diseased; it works best when used early (or preventatively in cases where you know you have a particular disease susceptibility). Severely diseased plants may need to be removed and disposed off site.