Keep an eye out for signs of rust, brown leaf blight, grasshoppers, and eriophyid mites. New stands are especially vulnerable to wireworms and cutworms. Look for the rust-resistant 'Climax' variety.
Still, rose rosette is a virus that spreads from the eriophyid mite and can cause contorted stems and leaves. Knock Out roses are susceptible to this virus. The only way to treat it is by digging ...