Follow these tips for keeping your roses healthy in Princeton, New Jersey.
All roses require some pruning each year, whether you have hybrid tea roses, climbers or knockout roses. Pruning is necessary to remove stems damaged by winter weather and to control size and train the plant for its optimal production of blossoms.
With any rose, start the job by first removing dead or damaged branches. Then begin to selectively remove more of the stems according to what is needed. This controls growth and encourages healthy new stems to produce blooms.
A popular, new, widely used rose in commercial landscapes, highway plantings and home landscapes is the double knockout rose. They are hardy and very resistant to black spot disease, the most common fungal disease affecting all roses. They bloom consistently through the summer until the fall frost. If they not trimmed, knockout roses will grow to about 5 feet high and can be utilized as hedges. Pruning knockout roses is very simple. Like other roses, they should be cut back before winter to around 30 inches high to reduce their loosening from the ground by winter winds. Then cut them back a little more in the spring. Start by first removing all broken or dead stems. To control size, cut them to about 20 inches. Soon after, they will sprout new stems (Green wood) that will generate many blooms. Light trimming of the stems from time to time may be needed to keep them trained through the summer.
HYBRID TEA ROSES
If you have purchased hybrid tea roses from a nursery, they typically have been pruned to 12 to 18 inches at the time of purchase. Pruning should be done each following spring. Routine excess pruning will negatively affect bloom emergence. Cutting to 15 to 18 inches in the spring is appropriate.
CLIMBING & RAMBLER ROSES
Climbing roses require some annual pruning to keep them managed on a trellis or fence. Prune them according to their growth habit, essentially "training" them to grow as desired. Begin by removing the very old and declining stems on both types of roses. Be careful not to cut them back as much as you would prune hybrid tea roses. Regular but moderate pruning of climbers will encourage a constant supply of younger, stronger blooming stems.
Need more help? Visit us at Princeton Lawn & Landscapes for all your pruning needs!