Pruning Hybrid Teas, Floribundas, and Grandifloras
To prepare for winter, prune out only diseased, damaged or interfering canes leaving the healthy canes to be re-evaluated in the spring. The canes to be removed should be cut flush with the bud union on a grafted rose or, if the rose is on its own roots, close to a major cane. Our persistent winds may necessitate tying the canes of the plant together and cutting all canes to the same height of two to three feet to improve stability and prevent heaving the rose out of the ground. If the rosarian has the creativity and wherewithal to insulate even five or six-foot roses from top to bottom, there is no real reason to cut them back at all. In real life, though, this is seldom practical.
When the danger of frost has passed and the winter protection is removed, select three to six of the newest and healthiest canes and prune out the remaining canes to the base of the plant. Most likely there will be signs of dieback (black) or even canker (brownish purple blotches) on the remaining canes. If this is the case, prune the canes below the markings. Cut until the inner material of the rose, its cambium, is white or greenish white–proof that it is alive. To discourage cane borers, do not fail to seal the cut end of the cane with a white glue such as Elmer’s or with nail polish–the color choice is left to the rosarian. Hybrid teas and floribundas may be sheared to15 to 18 inches above the bud union. Grandifloras or floribundas used to form a hedge may be left at 24 inches. The object of the pruning is to open up the center of the plant for air circulation and to prevent chafing of canes against each other–both causes of diseases.
Pruning takes place whenever a bloom is cut for a bouquet so it is important to maintain the health and vigor of the rose canes. The teas are valued because they, ideally, produce one flower per stem. Very often, though, surrounding the major bud there may be several more buds of varying sizes. These will bloom after the main bud has flowered and faded leaving a spray instead of the desired single stem. The grower, using his fingers or a toothpick to remove the side buds as soon as he sees them, will be rewarded with a single-stemmed rose.
The characteristic of grandifloras and floribundas to produce many sprays of flowers rather than single stems can be enhanced by removing the largest bud in the center of the cluster so the remaining buds will develop simultaneously. Secondary canes are always smaller than their parent cane, so do not encourage flowering on canes thinner than a # 2 Pencil. Cut above a five-leaf at a 45-degree angle away from the parent cane so the higher portion of the cane will protect the new cane emerging from the bud-eye at the base of that five-leaf.