Green Industry Resources
Hort Update- Seasonal Information for the Green Industry
Pruning Roses- Hybrid Tea, Shrub, Climbing & Rambling
Hybrid tea roses are the most popular garden rose, and 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 bloom on new growth, so 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.
In Nebraska 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 and, if found, remove one the branches so that they do not rub against each other and cause wounds.
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. In spring, plants are pruned back to 6-8 inches in height. Select the strongest 5 or 6 canes and cut them back to an outward facing bud. Remove all other canes back to the crown.
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 don’t be tempted to prune too early. Our last frost date in eastern Nebraska is approximately May 15th.
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. In the next few weeks, we’ll look at pruning roses, including shrub roses, climbers & ramblers, and hybrid teas.
Shrub roses should be pruned in early spring, late February or March, preferably while still dormant or pruning can be left until early spring, just as the new growth begins to emerge.
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. Make the cut at least one inch below the dead area. If there are no live buds, remove the entire branch or cane to the base of the plant. Examine canes carefully for canker (a darkened, sunburned-looking area) or other diseased areas. If disease is found, cut down to a good bud at least one inch below any evidence of disease. 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 and eliminates the development of many old, 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 1/3 of their canopy height removed.
Popular shrub roses that perform well in the landscape include older, traditional varieties like ‘The Fairy’, ‘Frau Dagmar Hastrup’, ‘Harison’s Yellow’, ‘Seafoam’, ‘Meidiland’ and ‘Hansa’. Newer varieties include ‘Nearly Wild’, ‘Knock Out’ and ‘Pink Knock Out’.
Climbing & Rambling Roses
In the first two or three seasons after planting, new climbing and rambling roses should receive little pruning, except to remove any winter-killed wood in spring. In subsequent years, prune ramblers and vigorous climbing roses soon after flowering. Be sure to remove all suckers, especially on grafted roses, to prevent the rootstock from overgrowing the grafted portion of the plant. (Remember that most named varieties of roses are grafted onto a species rose rootstock.)
Most climbing roses bloom on current season growth, and may bloom once or be repeat bloomers. These roses are often derived from hybrid tea roses and are not particularly vigorous, usually requiring little yearly pruning except to remove winter-killed wood, dead, diseased, or weak growth and old, unproductive canes. Pruning should be done in spring before new growth occurs. ‘Joseph’s Coat’, ‘Handel’ and ‘Don Juan’ are a few varieties of climbing rose.
Some varieties of climbing roses, often identified by the word ‘climbing’ in front of the variety name, originated as a tall sport from a hybrid rose variety, such as ‘Climbing Peace’. These roses should not be pruned back heavily within the first two or three years after planting, or they may revert to the bush growth form. Throughout the summer spent flowers on repeat blooming climbers should be cut back to the first set of five-leaflet leaves to allow for reblooming.
Climbing roses derived from Rosa wichuraiana, including ‘Alberic Barbier’, ‘Silver Moon’ and ‘May Queen’, bloom on one-year old wood, do not repeat bloom and tend to be very vigorous plants. One method of pruning these roses is to cut blooming canes back to the ground after flowering and leave any newly emerging shoots to grow and bloom the following summer.
Rambling roses are vigorous plants that produce small clusters of flowers only once during the growing season. ‘Excelsa’, ‘Dorothy Perkins’, ‘American Pillar’, and ‘Veilchenblau’ are a few examples of rambling roses. Rambling roses produce much more growth from the crown than climbing roses, and can easily become a tangled mass of branches if not pruned properly.
Nearly all ramblers produce flowers only on second-year wood and should be pruned in summer after blooming. Begin by removing diseased and dead canes.
Next, remove the older, gray-colored canes since most canes will decrease in flower production after only 2-3 years. Also remove weak, thin-diameter canes leaving only the most healthy, vigorous canes. Cut lateral (secondary) branches back to 8-10 buds and shape the plant as desired.