Q.Hello, I recently moved to a house in Maryland with well established shrubs of Knockout Roses. We kind of forgot about them for a
year and neglected them… Even last year they had some foliage damage consisting mainly in holes in leaves, but still had 2 beautiful and plentiful blooms. This year a small bloom in the spring, foliage is damaged, we finally decide to prune the overgrowth and clean some of this messy leaves. We gave also a treatment with neem oil and I am about to try insecticidal soap ( I noticed some beetle resting on leave and other tiny bugs under the leaves). We also started to fear of RRD because we noticed some reddish new leaves, some lateral red shoots somehow more juicy and full of plyable soft red thorns. I can attach photos. All the 5 plants seem to display some of the characteristic symptoms of RRD. Before cutting it down we would like a confirmation and if it is possible to have it tested to confirm. No houses around us seem to have roses planted our are the only ones. The plant has not been fertilized and taken care for 1.5 years at least… I really would like to save them as much as possible. Should a contact also a local agricultural disease center if RRD confirmed? Thanks for your help.
Thanks for sending the photos. Only the fourth photo sent shows anything that might be close to RRD. The other redish/maroon looking growth is healthy new growth that will turn more green as it matures. I would get some Bayer Tree and Shrub granules and apply the granules around the base of each rosebush per label directions for ornamental shrubs or shrubs. Work in lightly and water in well. Then after about a week, water the rosebushes with water that has both a product called super thrive and a root stimulator product in the same water, added to the water as if each were the only thing added per the label instructions. Water them with a fresh batch of the water mix the next 4 to 5 times they need watering. That should get them going well for you. The tree and shrub granules have a rose food and systemic insecticide in them that helps give the rosebush some good food and the systemic insecticide moves through the roses natural juices to get after hard to get bugs.