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 Company.
  
  

How Much to Prune

• Prune no more than one-third of the plant at one time, warns University of Georgia extension experts. Remove all damaged limbs or sections of the plant damaged by cold temperatures.
  
  

Touch-Up Pruning

• Knock Out Roses eventually shed their wilted blooms, but some gardeners prefer to snip those away promptly at mid-season for aesthetic reasons. It's also acceptable to lightly shape the plants during the year, if desired.