Enter the "pests". Knockouts are very disease resistant and hardier than most roses. So when my roses started getting holes in the leaves and leaves that looked like skeletons, I was quite concerned. That had never happened before. Turns out I had two different opportunists munching on my roses.
First came the sawfly larvae. They are little green caterpillars that like to hang out on the top and underside of the rose leaves. They nosh away on the soft tissue of the leaves. What remains is a skeletal, translucent leaf that dies off, leaving the bush looking scorched and disfigured. It's best to find these little guys early before they do alot of damage. We used insecticidal soap to get rid of the larvae along with just picking them off and squishing them.
Next came a rather beautiful eating machine which I have never had a problem with before, the Japanese beetle. This little guy is actually quite pretty, but he a big appetite and left my roses with holes in the leaves and buds that were disfigured. Apparently this year has been very productive for them and they've been doing significant damage. Japanese beetles also have an appetite for other things besides roses. I found them eating my basil! Japanese beetles are large and easy to see. They don't move quickly, which is convenient for manually picking them off and squishing them. My preferred method is to push them into container of soapy water. I would inspect my roses daily and pick off any that I saw. That along with insecticidal soap seems to have taken care of the problem. Now that it's August, their life cycle is winding down anyway.
These two insects can be very destructive. It's important to know about them and watch out for them so you can catch the problem early! I heard about the beetles before, but I really did not know much about these pests until this year. I'll be ready for them next year. If you have outdoor plants, especially roses, I hope you find this Musing informative and helpful.
Link below will give you information on sawfly larvae.
Links below will give you information on Japanese beetles.