An area of concern for many gardeners new to growing roses is pruning. Why do you have to prune roses? What kind of tools do you need? When is the best time to prune? How do you prune? Does it matter what type of rose it is?
Basically, pruning is done to improve the appearance of the plant, to remove dead or diseased wood, to let in sunlight and air to the center of the plant and to control the quantity and quality of the flowers produced. Deadheading, or the removal of spent blooms during the season, encourages more blooms (on continuous blooming varieties), improves the appearance of the plant, and removes potential harboring sites for disease organisms.
Prune rose bushes to a uniform height, between 12 and 24 inches; remove suckers below the soil line.
The tools essential for pruning roses are pruning shears, long handled lopping shears and a fine toothed curved saw. All should be sharp to produce clean cuts and to avoid tearing or crushing the stems. When buying pruning shears, look for the hook and blade type, which have two cutting edges like a pair of scissors. The anvil type pruners, with one cutting edge, will crush the stem. Long handled lopping shears are best used on thick canes or ones difficult to reach with pruning shears. A fine toothed curved saw is used for larger climbing roses. You might also want to invest in a pair of heavy duty gloves to protect your hands from sharp thorns.
In general, roses should be pruned just before growth begins in March or early April. The exceptions are old (heirloom) roses and some climbers that produce blooms on the previous year's wood. They should be pruned after they bloom.
Pruning Bush Roses
Following a logical sequence of steps while pruning will help make the job seem less complicated. The first step is to remove any dead, diseased or damaged wood. Cut the stems one inch below darkened areas, making sure you are cutting back to green wood. Make the cut at a 45 degree angle about 1/4 inch above an outward facing bud. Inspect the pith (center of the stem). It should be white. If tan colored, continue pruning sections of the stem until the pith appears white.
The second step is to remove branches that grow toward the center of the plant. This opens up the plant for better air circulation and allows sunlight to penetrate the inner portion of the plant.
The third step is to locate crossing branches and remove the weakest one. Crossing branches may rub against each other, causing abrasions that may serve as openings for disease organisms to enter the plant. Remove sucker growth, which is growth coming from below the bud union. Sucker growth is from the root stock and is a different rose variety; if not removed, sucker growth will crowd out the desired variety.
Finally, prune to shape the plant. Hybrid teas, grandifloras and floribundas can be pruned 12 to 24 inches in height, leaving up to 9 to 12 large (1/2 inch diameter), healthy canes. Old, shrub and species roses should be pruned lightly, removing no more than 1/3 of the growth. Miniature roses need only minimal pruning.
Many rosarians add one extra step to their pruning routine. After pruning, a water soluble, white glue (i.e., Elmer's) can be applied to the cut surfaces of the stems to prevent rose cane borers from entering.
Pruning Rambling and Climbing Roses
The procedures for pruning Rambling and Climbing roses will vary depending on the type of rose it is. A pruning basic that remains constant, though, is removing dead, diseased or damaged wood whenever noticed. This improves the appearance of the rose and removes places for disease organisms or insects to overwinter.
The characteristic that distinguishes a Rambling and a Climbing rose is their pattern of flowering. The Climbing rose blooms continuously throughout the summer, while the Rambling rose blooms once. The Rambling roses can be subdivided into three groups, all of which are pruned differently.
It is important to note that the shoots of all Ramblers and Climbers should be tied to a support in a near horizontal position. These shoots will produce flowering laterals along their length and provide a generous display of flowers. Vertical shoots will tend to produce flowers only at their tips.
Rambling Rose: Group 1
Ramblers in the first group are derived from Rosa wichuraiana, including the cultivars 'American Pillar,' 'Dorothy Perkins,' and 'Excelsa.' They flower on one year old shoots produced from the base of the plant. When planting new bare root plants, prune the canes to 9 to 15 inches. Train the vigorous new growth horizontally on a support. There will be no flowers the first season, but profuse flowering the next. Strong young basal shoots will develop, too. In late summer or early autumn cut the stems that flowered at their base and tie the new growth horizontally. A few old canes can be retained, if pruning all would leave the plant looking too sparse.
Rambling Rose: Group 2
Group 2 differs from Group 1 only in the position of the new canes. The new canes for Group 2 grow half way up the old canes, not at ground level. Like Group 1, flowers appear on one year old wood. The plant is pruned after flowering by removing old wood up to the new growth then securing the new growth horizontally to the support. Examples of cultivars in Group 2 are 'Alberic Barbier,' 'Albertine,' 'New Dawn,' 'Paul's Scarlet Climber' and 'Veilchenblau.'
Rambling Rose: Group 3
Included in this group are roses that are extremely vigorous, capable of growing 20 feet in one season. Examples are Rosa filipes 'Kiftsgate,' 'Francis E. Lester,' 'Wedding Day' and 'Paul's Himalayan Musk.' These roses are best used as a ground cover or to grow up into trees. Very little pruning is necessary, except when a plant begins to overwhelm a tree. Pruning can be done to reduce the size of the canes or whole branches can be removed at the base.
Climbing Roses
Climbing roses bloom continuously on the current season's growth. They are moderately vigorous and their flexuous stems lend themselves to supports, such as, fences, pergolas, arbors, and walls. Examples are 'Handel,' 'Iceberg,' 'Meg,' Rosa banksiae 'Lutea' and Rosa 'Mermaid.' When planting new bare root plants, trim the roots only, not the shoots. Tie the shoots to a support system to train. Early the following spring, while the plant is still dormant, shorten flowered laterals to four or five buds. If pruning an established climber, prune the flowered laterals in the spring, the same way you would a new plant. Remember to remove any dead or diseased wood or stems arising from below the bud union. For climbers that are several years old, some of the oldest wood can be removed at the base to encourage new growth.
Deadheading Roses
Removal of spent blooms, called "deadheading," is an important summer maintenance practice for roses, especially the continuous blooming varieties. Removing the spent blooms conserves the energy the plant would normally use for seed production, encourages repeat flowering, and removes potential disease harboring sites. Spent flowers may not be removed from species such as Rosa moyesii and R. rugosa because their large colored hips add another ornamental feature to the plant in the autumn.
To deadhead, remove the flower by cutting back, at a 45 degree angle, to the first outward facing bud in the axil of a leaf with five leaflets.
The continuous blooming climbing rose is deadheaded a little differently. Remove the spent blooms just above the foliage, making sure not to remove any of the foliage since new blooms will be produced from the leaves immediately below old flower clusters.
