To trim Knock Out roses, prune them during the second season of growth, trim them vigorously in late winter, and then shape the bush during the growing season. Remove dead or diseased wood, and cut away limbs that rub together. You need pruning shears or hedge clippers.Continue Reading
Prune a Knock Out rose bush once it reaches its second or third season of growth. Dip your pruning shears in a disinfectant before trimming.
When trimming the roses, cut the limbs at an angle. Trim the roses to just above the outside buds.
Trim a Knock Out rose bush vigorously in late winter before it starts growing. Make sure the buds are just starting to swell. Cut the old canes down by half to encourage growth.
During the growing season, trim the bush lightly and regularly to retain its dome shape.
Remove dead, damaged or diseased limbs throughout the growing season.To prevent diseases, thin the branches in the center of the bush, allowing air to circulate throughout the limbs.
Remove branches that cross or rub against other canes.