OKLA. CITY —
Hybrid tea roses, the most popular garden rose, require regular pruning to maintain vigorous growth, flower quality and quantity, and to remove dead, diseased, weak or broken branches. Hybrid tea roses have large flowers produced singly on long stems or in clusters and include common varieties such as Peace, Sterling Silver, Double Delight, Mister Lincoln and Tropicana.
Hybrid tea roses which bloom on new growth, are pruned in spring just as the buds begin to swell. The amount of wood removed depends primarily on how much winter injury has occurred however, pruning can also be used to manipulate the size, timing and number of flowers that a plant produces in the coming summer months. Like any blooming plant, rose leaves generate the energy resources required for flower development and it takes 25-35 leaves to create and bring into bloom one rosebud. Consequently, removing more or less foliage through pruning will affect the amount of flowers each plant can generate.
Moderate to light pruning is preferred. This technique will produce slightly smaller flowers in greater numbers and is achieved by pruning plants back to 12-24 inches in height or about half the branch length in spring. Completely remove dead, diseased, weak or broken branches by cutting them back to the crown. Also inspect the plant for crossing or rubbing branches.
Severe or “hard” pruning will cause hybrid tea roses to develop larger flowers, but blooming is delayed and fewer flowers will be produced overall. Severe pruning is recommended only on plants for exhibition or show.
A few last things to keep in mind include the following. Use sharp, scissor-type pruners to make the cleanest cuts. Make pruning cuts at about a 45-degree angle to facilitate shedding of water from the cut stubs. Always cut branches back to an outward facing bud and remove suckers originating from the rootstock. Deadheading, or removing spent blooms, will keep your plants blooming all summer. Cut the stems back to the first 5-leaflet leaf beneath the old flower. Finally, pruning too early in the season can cause plants to initiate growth that is damaged by late frosts, so do not prune prior to March 15.
Many gardeners are hesitant to prune landscape roses, fearing they will do something wrong and damage or kill the plants. However, pruning provides several benefits including improved flower quality. Pruning gives plants a better shape and maintains a plant size that fits into the landscape. Pruning also improves plant health by increasing air movement around and through plant foliage.
Shrub roses should be pruned in early spring, after March 15, preferably while still dormant.
Following a sequence of steps when pruning can make the process seem less complicated. First, remove any dead, diseased or damaged branches. Remove dead wood to the nearest healthy bud. Pith (located in the center of the stem) should be creamy white on healthy, live wood, not brown or gray. If the inside of the stem is brown, prune the cane back farther. Prune to where the pith is healthy or to the plant’s crown.
Next, remove up to one third of the oldest, woodiest stems, cutting them back to the plant’s crown. This encourages the growth of new, vigorous stems from the plant crown. This eleminates woody branches with poor flower production. It also increases air circulation through the plant, reducing potential for disease problems.
Finally, shape the plant as needed keeping in mind that shrub roses should not have more than one-third of their canopy height removed.
Popular shrub roses that perform well in the landscape include older, traditional varieties like The Fairy, Frau Dagmar Hastrup, Harrison’s Yellow, Seafoam, Meidiland and Hansa. Newer varieties include Nearly Wild and the Knock-Out series.
RAY RIDLEN is an agriculture/horticulture educator for Oklahoma County OSU Extension Center, 930 N. Portland, Oklahoma City. He may be reached by calling 713-1125.