Knock Out roses are a new variety that make rose gardening a breeze. Whether you choose a Knock Out rose tree or bush, this plant offers prolific blooms with little maintenance. The roses are resistant to disease, including black spot, thrive in most soils and are even drought-tolerant. These roses even self-clean---they require no dead-heading because spent flowers drop and new ones emerge. Knock Out rose trees are hardier than most rose trees, although they do benefit from winter protection.
Cut out diseased and dead wood with your pruners from early spring to fall. Discard all branches promptly to avoid introducing diseases, especially if you have other rose varieties in your garden. While Knock Out rose trees are disease-resistant, good hygiene practices will ensure healthy plants.
Rip out suckers by grasping them between your fingers and pulling. Suckers are spindly, vegatative growths that sprout from main limbs. Pruning them will cause them to re-grow.
Prune back the tips of your rose tree throughout the growing season to maintain its shape. Rose trees don't require severe pruning, but if you want to reshape the tree, prune in early spring when buds swell, but new growth hasn't begun. Make cuts 1/4 inch above an outward-facing bud. Cut at a 45-degree angle so water will run off the cut.