Pruning roses is a must-do job for spring. Your plants will reward you with beautiful blooms and vigorous health that helps ward off disease. This article provides the basics of rose pruning, but check with your local OSU Extension office if you have additional questions.
Why prune roses?
Roses should be pruned to encourage new growth and a succession of flowers throughout the growing season. Roses are pruned annually to encourage healthy plants.
If pruned improperly, plants will have weak canes, poor form and little air circulation. Underpruning is the most common cause of an unproductive rose. However, a rose left unpruned for several years can be rejuvenated by pruning.
When to prune?
- Winter pruning: In the Willamette Valley, prune from mid-February to early March, when the weather is conducive for the plants to start growing. Earlier pruning (before last hard frost or forecasted bad weather) may cause die-back that necessitates repruning. The later you prune, the later your first bloom flush will occur.
- Bare root roses at planting: To encourage the plant to concentrate on growth, prune the canes to 6 inches or less.
- Fall pruning: Take several inches off Hybrid Tea, Floribunda, and Grandiflora to reduce wind damage.
Repeat blooming roses, including climbers, will bloom more profusely if faded blossoms are removed. Cut the stem back to an outward facing bud, cutting at a 45-degree angle to increase air circulation and encourage the plant to put nutrients and energy into the bud to produce more flowers.
Purchase the best garden tools that you can afford. This is particularly true for cutting tools. When you shop for them, be sure that they feel comfortable in your hand.
- Pruners are the most useful cutting tool. Bypass pruning shears will cut a woody stem up to three-quarters of an inch thick. Do not try to exceed their capability as you may damage both the tool and the plant. Never cut wire with the blades. Keep your pruner sharp so it makes a clean cut.
- Loppers usually have long handles that make it easier to cut a thick cane. Bypass loppers are particularly effective. Loppers come in several sizes, so try a variety before you purchase one.
- Pruning saws allow you to cut almost anything with ease. Pruning saws come with wooden handles, and several models have a handle that the blade folds into for storage.
- Alcohol. When pruning roses, clean your shears by dipping the blades into alcohol before working on each plant. This prevents spreading plant disease.
- Gloves are optional but leather gloves are useful when pruning roses.
The pruning cut
Make a clean 45-degree cut on a downward slant, away from the bud, about a quarter inch above an outward facing bud eye. Cutting to an outside bud increases air circulation. Strip the bush of foliage two weeks before pruning to cause new buds to swell. Cut rather than tear Hybrid Tea leaves to prevent damage to dormant buds.
One method of locating the bud eye is to strip the rose bush of foliage two weeks before pruning, and nature will send an urgent message for foliar rejuvenation. The new eyes will swell and make it easy for you to see them. If you choose to remove the foliage of your hybrid teas, be sure to cut the leaves off and avoid tearing them as this will damage the dormant eyes.
Prune annually to encourage healthy plants. Start by removing dead, dying or diseased canes. Cut canes to white or pale green live pith. Brown coloration indicates a dead or dying cane and may require pruning to a bud eye lower to the crown to find live pith.
Create a vigorous rose by selecting from three to six strong basal shoots from the previous year’s growth to keep. Remove all other growth then prune back the selected canes.
Most pests and diseases are not killed by winter weather but wait out the season in soil, inside leaf buds, and on the canes of your roses.
You can eliminate some pest problems by using a dormant spray after you prune. The spray needs to be applied when the bush is dormant early in spring before the rose sends out new shoots. The dormant oil is not harmful to the environment, and it coats canes, buds, and leaves where it suffocates pests and the spores of overwintering fungi.
A rose needs to have the correct form for its variety, and it likes to have plenty of air circulation. Crossing canes are not good for the plant as that tends to promote damage to the canes, and that encourages disease. Know the type of rose you have. You don't want to prune your favorite climber as if it were a hybrid tea.
- Hybrid Tea-Grandiflora: The natural plant shape is like a large vase. Deadhead during season to promote rebloom. Moderately prune to 12–18 inches.
- Floribunda: Generally a larger plant than hybrid tea roses and have flowers in clusters. They are pruned not so severe. Remove interior lateral canes to promote air circulation. Moderately prune to 24-36 inches.
- Climbers: Repeat bloomers should be pruned while dormant. Remove all twiggy, dead or nonproductive growth. Only laterals coming from the main cane should be pruned. Leave three to five eyes on each lateral. Major canes are maintained horizontally to promote maximum bloom.
- Miniature roses: Prune to shape by cutting back to outward bud. May be sheared.