Every gardener loves roses. When left unpruned, this garden beauty can become a tangled mass of brambles with few small flowers. Proper pruning encourages the rose to thrive, developing larger blossoms and strong branches. It allows air and sunlight to circulate within the center of the plant, which reduces disease problems.
It is usually safe to prune roses in northern Nevada around April 15, unless we are still experiencing freezing weather. However, in colder areas you may want to wait a couple of weeks.
Sharp, clean and sterilized tools are critical to rose pruning success. You will need a pair of bypass pruning shears, long-handled bypass loppers for thick canes, a fine-toothed curved saw for woody canes and of course, long gloves! Have a disinfectant on hand, such as isopropyl alcohol, Lysol spray, or 20 percent bleach to water solution, to sterilize your tools between cuts. Another essential is a non-toxic, non-petroleum-based white glue to seal freshly pruned areas to prevent boring insects.
In Nevada, we prune roses less severely than in milder climate areas of the country, because of the potential for late freezes, drying winds and extreme sun. Start the pruning process by removing the dead, damaged, blackened or crossing canes first. The next steps depend on the type of rose you are pruning.
For hybrid teas, the traditional cut-flower type of rose, or for grandifloras, which produce flowers in multiples but grow like hybrid teas, leave five to six of the strongest canes 20 to 30 inches long. Remove only canes three years old or older. Make a 45-degree angle cuts one-quarter inch above a bud. Floribundas, also multiple flower producers, have a shorter growth habit, and are pruned to a shorter height leaving more canes. Train and prune climbers to a horizontal pattern for greater flower production, removing any skyward pointing shoots.
No matter what type of rose, cut out any suckers, the shoots growing below the graft union, the swollen bit just above the ground. After sterilizing your shears between cuts to reduce the spread of disease from cane to cane, seal any cut one-quarter of an inch or larger with white glue.
After pruning, put all the cuttings and old leaves into the trash. Rose cuttings are not good for composting due to the prevalence of disease. Be sure to groom your roses regularly during the growing season to encourage additional flower production.
Call University of Nevada Cooperative Extension at 887-2252 or email firstname.lastname@example.org for a copy of “Pruning Roses in Northern Nevada” for more detailed information.