Knock Out roses (Rosa x "Radrazz"), hardy in U.S. Department of Agriculture plant hardiness zones 5 through 11, were bred to be particularly resistant to a number of conditions, including cold weather, disease and pests. Unfortunately, deer will still eat Knock Out roses. However, the deer will not kill this variety of rose plant.
Deer and Roses
Deer are herbivores and forage for a wide range of plant matter, including trees, shrubs, grasses, ornamental plants and garden plants. Deer can do considerable damage to a plant. Despite Knock Out rose plants having thorns, deer will not hesitate to eat them.
When a deer eats a rose bush, it may take the plant all the way to the ground. The rose bush appears to have had a severe pruning after a deer has grazed it. Fortunately, Knock Out rose tend to thrive when cut back hard in late winter, and will regrow from the roots in spring in their USDA hardiness zones.
Deer can be discouraged from eating Knock Out roses through the use of repellents such as soap, bloodmeal, mothballs and commercial chemical repellents, or by encircling the rose plant with welded wire no larger that 2-inch by 4-inch mesh.