This is a question that anyone who has ever owned a Knockout Rose bush asks themselves quite often. “Can I cut back my knockout rose bush?” That is a really good question, especially now that the frost has come to many parts of the country and these roses are still blooming nicely, but are very large and almost scraggly looking.
Here is my personal experience and opinion on when and how to cut back knockout roses. The first answer is cut them back much and often throughout the season to control the fullness of the plant. The second answer is cut them back anytime they are too large for the area. The third answer is cut them back as far as you would like, as often as you would like. The fourth answer is start back at the first answer if you have any more questions.
“Do I need to worry about them getting frosted on?” Honestly, I have never seen one get damaged because of cold weather. These things will just grow and grow and I have seen them bloom here in Nashville until about Christmas time. Once they get a lot of cold weather, they will drop a good portion of their leaves and sit still through the winter. This is a good time to prune them as well.
So let’s recap with an old church song…Prune them in the morning, Prune them at noontime, and Prune them in the evening…Prune them, Prune them, Prune them when the sun goes down. Or something like that!!