Pruning shrub roses is often a harrowing endeavor for many gardeners, but is required to shape the plant and improve the quality of the flower. Pruning prevents the development of fungal infection by improving air circulation throughout the rose shrub plant. Shrub roses require pruning in the early spring, in late February or early March while the plant is still in its dormancy phase, according to the University of Lincoln-Nebraska Extension.
Remove dead diseased and damaged branches first, recommends the University of Nebraska-Lincoln Extension. Remove dead wood as close to the nearest, healthy bud as possible, cutting at a 45-degree angle.
Cut back dead or old wood until you see creamy white pith or healthy live wood. If the inside of the stem is brown, prune back farther, recommends the University of Nebraska-Lincoln.
Remove an entire branch if there are no live buds as the entire branch is dead.
Examine rose canes for cankers, which appear as dark areas. Cut the can close to the next healthy bud, as the canker may develop into disease.
Remove one-third of the oldest, woody stems from the shrub rose bush, recommends the University of Nebraska-Lincoln. The University of Illinois further recommends removing weak canes that are thinner than the diameter of a pencil.
Remove suckers from the bottom of the shrub rose, recommends the University of Illinois. Suckers are outgrowths from the root of the rose bush, and are not part of the main plant. Dig down to the root of the rose bush and remove the sucker by hand. Cutting suckers encourages it to regrow.