The practice of pruning roses is intimidating to many gardeners, but it is actually very good for the plants. Becoming an accomplished rose pruner takes time and practice, but keep in mind that it is very hard to kill a rose with bad pruning. While there is a great deal of disagreement among rose experts regarding how and when to prune roses, it is generally agreed that most mistakes will grow out very quickly and it is better to make a good effort at pruning roses, even if you make a few mistakes, than to let them grow rampant.
Why You Should Prune Roses
Newcomers to grown roses can rest assured that roses are forgiving when it comes to pruning and that there are several advantages to regular pruning:
- Pruning encourages new growth and continued blooming.
- It removes dead wood and reduces the chances of diseases introduced by pests.
- Pruning helps improve air circulation, reducing the chances of fungal diseases such as powdery mildew and black spot.
- It helps to shape the plant, which is essential for vigorous growers that can easily grow out of control.
Tools and Supplies You Will Need
Most gardeners already own most of the supplies needed to correctly prune roses. Quite important is the protective clothing necessary to protect hands and wrists from being pricked by the sharp thorns.
Tips for Basic Rose Pruning
Keep these things in mind for correct, trouble-free pruning of roses:
- Use clean, sharp tools. Clean cuts that don't crush the canes are better for the plant.
- Look at the overall shape and health of the plant, but begin your pruning from the base of the plant.
- Prune to open the center of the plant to light and air circulation.
- Make your cuts at a 45-degree angle, about 1/4 inch above a bud that is facing toward the outside of the plant. Make sure it is a clean cut, not ragged.
- Remove all broken, dead, dying or diseased wood. This includes any branches that look dry, shriveled or black. Cut down along the cane until the flesh exposed by the cut is white.
- Remove any weak or twiggy branches thinner than a pencil.
- If cane borers are a problem in your area, seal the cut with a white glue.
- Remove sucker growth below the graft. Suckers growing up from the graft will have no flowers at all or flowers that are inferior to those growing from the grafted branches.
When to Prune Roses
Timing is determined by the class of the rose plant and the hardiness zone in which it is being grown. Most rose pruning is done in the spring, with the blooming of the forsythia as a signal to get moving. If you don't have forsythia, watch for when the leaf buds begin to swell on your rose plants: At the point where the bumps on the canes get larger and reddish in color, it's time to prune. You should prune before those buds break open, right after nightly hard frosts have ended in your region.
Hybrid tea roses are the most particular about pruning. If you don't know what type of rose you have, watch the plant throughout the growing season. If it blooms on the new growth it sends out that season, prune while the plant is still dormant or just about to break dormancy. If it blooms early, on last year's canes, don't prune until after flowering is completed.
General Pruning Guidelines by Rose Classification
Proper pruning of roses varies depending on the type and classification of the rose. Make sure you understand your rose's classification before you prune.
Roses that Bloom Once, on New Growth
- Modern ever-blooming roses and floribundas: These bloom best on the current season's growth. Prune hard (1/2 to 2/3 the plant's height) in the spring and remove all old woody stems. Leave three to five healthy canes evenly spaced around the plant. Cut them at various lengths from 18 to 24 inches, to encourage continuous blooming.
- Hybrid teas and Grandiflora roses: These also bloom on new wood and should be pruned in early spring. Remove dead and weak wood. Create an open vase shape with the remaining canes by removing the center stems and any branches crossing inwards. Then reduce the length of the remaining stems by about half or down to 18 to 24 inches. You can allow the older, stronger stems to be a bit longer than the new growth. During blooming season, deadhead blooms to a strong node. Rip out all suckers.
Roses that Bloom Once, on Old Wood
- Ramblers: Prune to remove winter damage and dead wood or to shape and keep size in check. Ramblers bloom only once and can be pruned right after flowering, all the way back to 2 to 3 inches if you wish. They will quickly regrow and you won't lose any flowers for the following season.
Roses that Are Repeat Bloomers
- Modern shrub roses: The shrub rose group is one of the repeat bloomers, flowering on mature, but not old, woody stems. Leave them unpruned to increase vigor for the first two years and then use the "one-third" method. Each year remove one-third of the oldest canes, in addition to any dead, diseased or dying canes.
- Climbers: Climbers or ramblers may repeat bloom. Prune these types early to remove winter damage and dead wood. Prune again, after flowering, to shape and keep their size in check. Remove and replace old and weakening long canes as needed.
- Bourbons and Portland roses: These will repeat bloom, blooming on both new and old wood. Prune them to remove dead wood before flowering begins. A harder pruning and shaping can be done after the first flowering is completed.
Roses Requiring Minimal Pruning
- Alba, Centifolia, Damasks, and Gallica roses: This group blooms only once, producing flowers on old wood; they don't require much pruning at all. Prune only to remove dead or thin wood and to shape the plants. Pruning should be done after flowering is complete.
- Miniature roses: Prune only to shape the plant. Cut back to an outward facing bud after blooming.