Q. I’ve heard two theories about pruning roses and of course, they have opposite approaches. One method suggests pruning severely to keep the plants contained and from out growing the area. The other way suggests moderate pruning to encourage root development. My roses are young bushes, less than three years old. Which approach should I use and when is the best time to prune them.
A. Roses establish themselves in the first growing season. In addition, our mild winters, allows the root system to develop and expand during the dormant season unlike other areas where the ground freezes. The roots develop on their own without any additional help. At three years old, your roses are quite mature. Thus, I wouldn’t be concern at all with the moderate pruning approach. Instead, I’d be pruning to contain the bushes to the desired area. This now leads us to the second part of your question, when to prune roses? My answer is year round. The classic definition of pruning is “To cut off or remove dead or living parts or branches of a plant, to improve shape or growth.” Hence, roses are pruned throughout the year not just in the winter months, as the cutting off of the spent flowers is a form of pruning. Roses are vigorous growers. Depending on the type, they can produce four to five feet of new growth annually. The winter pruning reduces this growth along with removing the dead wood and the rubbing and crossing branches. After each flowering period, you should remove more than just the spent flowers. It is at this time, you have the opportunity to reduce the lateral growth and the height, so they don’t merge with its neighbors or block the view of what’s planted behind them. The amount varies depending on how close the bushes are planted next to each other. This is an important point to remember. It prevents you from allowing the bushes to out-grow the desired space as you’re managing the growth throughout the growing season. This is usually over looked or forgotten. There is no exact date when to prune roses. Rather, it’s a period or window of time when the activity occurs. In the Bay Area, the traditional winter pruning season is from mid November through the end of February. The early season pruning is rarely done, as the bushes are still blooming then the holidays takes us away from the garden. By default, January and February has become the primary months to prune. Roses still can be pruned back severely in late March with the new growth emerging. The only drawback is that the first flowering period is delayed.
Some additional thoughts: January and February is an excellent time to transplant roses but I’d prune them back first. You need not delay pruning because the bushes are blooming, just pick the flowers and enjoy them indoors. After pruning, any remaining foliage should be stripped off, clean up all the litter under the plants, and spray them with Lime Sulphur.
