Q How do I prune and take care of Double Knock Out roses?
A Knock Out roses have become wildly popular in recent years for several very good reasons.
The plants are tough and resistant to disease (though not totally disease-free). They have a pleasant bush-type shape. They are easy to establish and grow. They produce blooms all summer with a minimal amount of attention. In short, they are about as easy as roses can get.
You can allow Knock Outs to grow tall or keep them shorter and shrubby. You can even cut tall ones back sharply, and they will branch out and grow.
These are shrub roses, not hybrid teas. In general, you should plan on pruning shrub roses in late winter or early spring. Usually, we are advised to trim back one-third of the foliage in late winter.