By John & Louise Clements
The purpose of pruning is to keep the bush fresh and open so that old growth is removed and thinned which helps to prevent disease and encourage better flowering. Good air circulation is important for a healthy bush. It also helps to keep the rose bush in proper proportion to the rest of your garden plan.
WHEN TO PRUNE?
There are often differing opinions about when to prune roses. Some people say to prune in the fall, some say in the spring. Heirloom says: BOTH. (Note: do not prune once blooming roses in the fall or spring. See specific instructions below.)
In the Fall: Prune to prevent wind whipping and scarring by long canes. Pruning long canes will also prevent the possibility of the roots being loosened as a result of strong winds. Winds also pulls the moisture out of a plant. Light pruning would be a good winter protection measure. Shorten long canes to 3-4 feet.
In the Spring: Prune to shape the bush, clean out dead wood and worn out or weak, spent canes. Prune in early February west of the Cascades or just as new growth starts.
East of the Cascades prune in March or April, as you would do in other cold weather areas across the United States. If you get a damaging freeze below 25 degrees after early spring pruning, you may have to re-prune shorter but this shouldn’t happen very often. Wait until damage is visible before re-pruning (usually about two weeks). Sprinkle a handful of Epsom sales around the base of the bush. This adds magnesium. When the soil warms as the weather improves, magnesium will be available naturally. Adding it now gives the plant an early boost.
Prune in January in California and other warm weather areas.
For repeat blooming Shrub Roses and David Austin’s English Roses and Hybrid Tea Roses.
In the spring remove dead wood and canes that cross over each other. Thin so that the bush is open and ready to accommodate the new growth. Prune to an outside facing bud and cut the cane at a 45-degree slant about ¼ - ½ inch above the bud eye with the lowest end of the slant being on the opposite side of the cane from the bud eye. The slant is to keep water from collecting on the end of the cane. If you have only a few bushes, you may want to seal the ends of the pruned canes with Elmer’s Glue. We don’t do it and it’s not really necessary unless you have trouble with rose cane borers. Generally prune to two to three feet. Prune to healthy growth, which shows a pure white or light green center. Brown centers are a result of winter damage and the cane may die before completing the season. The shorter you prune—the fewer the blooms. The taller you leave the canes the more blooms will be produced but they will be smaller. Hybrid Tea roses may be pruned as short as 8 inches or least at 15 inches with flower production in proportion to the height to which the bush is pruned. Shorten long canes in the fall to 3-4 feet.
ONCE BLOOMING ROSES
Old garden roses that bloom just once a year MUST RETAIN their old wood for the following years blooms. This is growth that appears the year previous to any bloom it produces. These once bloomers should only be pruned immediately after their blooming period is finished, which is generally around July 15th. They can be pruned to 15 inches every other year with no damage. This keeps a large bush within bounds and provides shaping. This is the way we prune many once bloomers at Heirloom Roses. If you do not mind the size of the bush then only clean out the dead canes or growth which in undesirable to you.
REPEAT BLOOMING CLIMBING ROSES
Deadheading (removing spent blooms) may be done If possible to reach them. This encourages more blooms. Long unsupported canes or canes you do not want should be pruned in the fall. In the spring prune to the desired number of canes (generally no more than four to six) remove dead growth and tie to the supports. Do not prune or shorten the canes or you will be cutting off next year’s blooms. After the plant is fours years old, prune out one or two of the oldest canes each year to renew the growth.