Knock Out Roses getting TKO

Asked July 3, 2016, 10:53 AM EDT

I have several Knock Out Roses, and the ones facing a southern exposure look awful. They started out with a lovely spring bloom. Now, the flowers look stunted, the buds form but don't open and shrivel up and turn brown. Also noticing m any spots on leaves, is this anthracnose? Eight bushes are affected. I've been trimming off the affected blooms but there are many of them.

Sussex County Delaware

1 Response

Your Knockout roses may be suffering from Botrytis Blight. However, for a definitive diagnosis and management recommendation please take a sample of a cane that includes blooms and buds as well a woody section. Bring it to your County Extension Office at 16483 County Seat Highway, Georgetown, DE weekdays between 8am and 4:30pm.