Shrub roses should always be pruned by cutting stems back to a healthy bud.
Knock Out Roses Pruning Steps: To maintain a size of 3–4’ w x 3–4’ h, Knock Out Roses should be cut back once a year to 12” high. Check your rose bush from time to time in late winter/early spring, and when you start to see new shoots growing from the canes on your rose bush, that’s a Email: [email protected] Jul 21, When to Prune. Prune Knock Out Roses in late February, recommends the University of Georgia Cooperative Extension Service.
The last hard frost typically has occurred by this time, making pruning safe, according to the rose's developer, The Conard-Pyle stumpdrop.club: Dana Hall Mccain. A: Much depends on how high you want them to be in summer.
I like mine 36 inches tall, so I prune to 18 inches in January, February or early March. They will grow to five feet tall if left unpruned but they look a bit open and ragged for my taste at that size. Cut out any dead branches first, then any that cross through the stumpdrop.clubg: Winder GA. May 18, Knock Out blooms continuously from April thru October if the faded blooms are removed regularly. I visit mine every week and twist off the faded flower buds. Every four weeks I cut long stems back.
This two-step process keeps new growth coming and removes the hormone-filled hips that tell the rose to bloom more slowly. Remember that your Knock Out will make flowers 16 inches Missing: Winder GA. Mar 01, Maintainence pruning can be done during the resting phase. It is also a good time to cut off withered blooms, but not necessary.
Heavy pruning though should be done in late February in warm, southern climates or in March for the moderate to cool climates. The only time I do not recommend pruning is in the stumpdrop.clubg: Winder GA. Mar 26, A resting phase is a good time to prune. About the only time not to prune is late summer and early fall, as this might encourage late growth that wouldn't harden off in time for winter. In the North, winter is not a good time to prune, but winter is just fine in the stumpdrop.club: Steve Bender.