Answer: You can cut Knock Out roses back at any time of the year. I generally cut mine down in early spring, reducing them to about 12" and then clip them back periodically during the summer months so they won't get unruly. They grow nicely all summer and the following spring I prune them back again. You can keep yours about 3' tall with continuous light pruning. This will keep them full and flowering most of the summer. Enjoy!
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