Q: My Knock Out roses are blooming beautifully, but now something is starting to eat the leaves. What is it, and how do I stop it?
A: They are difficult to see, but tiny whitish green worms with orange heads on the undersides of the leaves are likely the culprit! These are the larvae of the Rose Sawfly, and they eat holes in your rose leaves. Two methods of control are an insecticide like imidacloprid, or neem oil, which is effective in targeting immature insects in active growth. Neem oil is labeled as organic, while imidacloprid can be harmful to desired pollinators. ALWAYS read and follow the label directions, and do some research before applying any pesticide. Do not spray blooms directly with pesticides. If the bloom needs to be sprayed, apply the pesticides in the evening hours. It is not recommended to apply pesticides on very hot days, with temperatures above 90°F. The active ingredients in some pesticides can vaporize and drift onto non-target surfaces.