Knock Out roses are a popular variety for growing in gardens because they bloom prolifically and offer optimal resistance to disease. Pruning is essential to keeping these roses looking their best and giving them the best chance to remain healthy.Continue Reading
Knock Out roses should be allowed to complete two or three growing seasons before any pruning takes place. Cutting the bush before it's fully grown may damage the young plant. A Knock Out rose bush is considered fully mature when it's 4 feet high and 4 feet wide.
Remove dead flowers from the bush as soon as they begin to wilt. At this time, also do some light cosmetic pruning, shaping the stems and cutting away stray branches. Use a pair of garden shears for cutting, and remember to wear work gloves when cutting a thorny rose bush.
In the late winter or early spring, shortly before the start of the growing season, do a heavy pruning on the Knock Out rose bush. Cut back the large, healthy stems so that they're about 2 feet shorter than you want them to be at the end of the growing season.