Knockout Roses Dying
My mass planting of Knockouts on our waterfront side (Nanaticoke River/Tangier Sound) is dying from the ends of the mass toward the center. The die-off proceeds as main branches die sequentially. One of the bushes has had RRD in the past but has survived. Plants are 12 years old and this process began over the past couple of years. We have drip irrigation and the planting has thrived up until this process began. Photos attached of both healthy plants in the middle and diseased ones on the periphery, Would appreciate advice and/or a visit from the expert.
Wicomico County Maryland
We are not able to see enough detail in your photos to be able to give you a good answer. We need photos that are in focus and fairly up-close.
You do not mention rose rosette symptoms on your struggling roses, but please be aware that the disease is systemic and thus, even though when cut down it appears to grow new healthy growth, it is still infectious and can spread disease to your other shrubs.