Roses have traditionally been linked to love and romance, beautiful parks and landscapes, gracious homes and their beautiful yards, celebrations, weddings, and funerals. They appear in many colors and styles, from tea roses to climbers. Some roses have fragrances that can be enjoyed from a distance while others are more subtle or have virtually no scent at all. What’s not to love about roses? A rose lover seems not to mind even the thorniest stem, for the pleasure presented by the rose far outweighs the danger of the thorn.
Upon moving from Texas, my yard was planted in many species of decorative plants but my favorites are the Lady Banks rose, which blooms in the Spring, a pale pink tea rose and the red Knockout rose.
One of the most prolific and hardy roses in recent times has been the Knockout rose. It has been resistant to mildew, black spot, and mites. It produces a glorious abundance of blooms from early Spring until the first heavy frost in the Fall. It is heat and drought hardy and requires only minimal feeding and care. Now it seems it has encountered a disease it cannot overcome. Rose Rosette disease is caused by tiny bugs that carry the disease from shrub to shrub. Its name is Phyllocoptes fructophilic and is a wooly mite. They are far smaller than the more common spider mite and are difficult to see and identify.
Unfortunately, miticides, successfully used against the spider mite, do not appear to have any effect against the eriophyid or wooly mite, and there is no cure for Rose Rosette disease. The affected shrubs should be removed from the bed as soon as the condition is detected to prevent its spread to other shrubs. The problem is not is transmitted through the use of pruning implements.
After identifying the root of the unfortunate disfigurement among the Knockout roses, and after reading the advice of others advocating the removal of all of the affected plants, do you feel that this plan must be followed rather than pruning the plants back to healthy growth and waiting to see the outcome? The worst that can happen is that the grower ends up with no roses at all, so why not surgically remove the diseased growth and patiently wait to determine if at least some of the plants survive? The prospect of a Spring without roses is a sad one indeed!