Knock Out roses require fall pruning

Published 12:00 am Wednesday, October 2, 2013

Known for their disease resistance and seemingly endless blooms, Knock Out roses have become a popular addition to the home landscape over the past 10 years. For the most part Knock Out roses require little maintenance or extra care. Size can become an issue, however. Pruning them is not difficult and will help to keep your bushes’ dimensions in check.
Knock Out roses greatly benefit from two major prunings each year. The first of the major prunings should be done anytime from late January to mid February. Up to two-thirds of the bush may be removed during this late winter pruning. The second of the major prunings can be done now, late August through early September. The second pruning is normally not as severe at the first. At this time plants are generally only cut back by about one-third of their original height.
A sharp pair of bypass-type hand pruners can be used to make most cuts. Cuts should be made at an angle slightly above the nearest bud. Loppers may be required for some larger branches. Wear sturdy leather gloves and long sleeves while working because no matter how careful you are, thorny roses can painfully puncture or scratch your hands and arms. Dead and damaged branches can be removed anytime throughout the year. The same goes for deadheading old flowers.
Although there are guidelines and recommendations, there is no set way to prune Knock Out roses. A good rule of thumb for a bush that has grown too large is to decide what size it needs to be for the location and then cut it back about one foot shorter than that desired height. If you want your rose bush to continue to fill in a space or form a screen a light pruning is all that may be required.
For more information, contact the St. John Parish LSU AgCenter Extension Office at 985-497-3261 or visit
Mariah Bock is the LSU AgCenter County Agent for St. John the Baptist Parish. She can be reached by email at