By JASON GRAVES
K-State Research and Extension Central District Horticulturist
Pruning is an important practice on roses. Proper pruning will keep roses vigorous and will encourage more flower production. In general, the best time to prune roses is in the spring before much new growth appears and after the danger of a hard killing frost has passed. Now is a good time to prune and here are some pruning tips to consider.
For all roses
For all roses be sure to remove any dead stubs, otherwise, canker fungi can invade stubs and progress into healthy tissue during the summer months. To remove stubs, use sharp shears and make a cut at a 45-to 50-degree angle about a quarter-inch above a healthy bud.
Shrub roses
Pruning of shrub roses focuses on removing the following: all dead wood down to the crown or one inch into the healthy green canes, all signs of cankers (dark sunken areas), all weak, spindly or deformed growth (rule of thumb is to remove anything smaller than the thickness of a pencil), canes growing toward the center of the plant, all suckers down to the crown, and thinning out remaining healthy canes to the desired shape and height.
Hybrid tea roses
Three pruning styles are used with hybrid tea roses – each with its own specific purpose:
Heavy or Severe Pruning – Usually done on well-established, vigorous plants. This is intended to produce large, showy flowers. To do this, prune back to three or four healthy canes with three to six eyes per cane. Canes are normally 6-12 inches long.
Moderate Pruning – Is done on well-established, healthy plants. It is designed to increase the number of flowers produced rather than increase size. Prune stems to 12-18 inches long. Leave between five and seven canes with at least seven buds per cane.
Light Pruning – This rejuvenates plants after years of neglect, but can also be used on newly- established plants. It helps to maximize leaf area for energy production and renewed vigor. Leave five to seven canes that are about 18 inches or more in length.
Climbing roses
When pruning climbing roses, follow the above recommendations for pruning shrub roses. Large-flowered climbers and climbing hybrid tea roses should be treated in a way similar to shrub-type roses, pruning in the spring before new growth appears. The spring-flowering climbers should be pruned after they have flowered in the spring.
The canes on most climbing roses remain healthy for about three to four years, which makes it necessary to remove some of the older growth every year. The canes should be cut to a height of 18 to 30 inches to help shape the plant.
Ramblers and fast-growing climbers do best if they are pruned after they have flowered for the first time in the spring and may occasionally need to be shaped once or twice through the summer months.