I have four fairly large knock out roses and they now have holes in their leaves along with white spots on the leaves. What could be causing this and how do I fix it? Sharon Cohen Scohen0525@yahoo.com
Certified GKH Gardening Expert
Hi Sharon. It sounds like you have a beetle problem. They poke holes in the leaves to such out the natural juices for their survival. You can spray the rosebushes with an insecticide such as Bayer Complete or give them some Bayer Tree and Shrub granules or Bayer Rose & Flower granules, they are a systemic that is taken up by the root system to stop such attacks. The white spots could be the onset of Powdery Mildew, or if the move they could be mites or some insect. For the powdery mildew, I spray my roses with an earth friendly product called Green Cure at the Cure Rate listed on the label. It can be purchased on-line if you cannot find it locally, check out the Planet Natural website.