Deadly virus killing roses in Fort Worth, across the state


A killer disease has set its sights on America’s most beloved landscape shrub, the rose.
Even the seemingly invincible Knock Out roses, with their reputation for superior pest and disease resistance, have succumbed to a virus known as rose rosette disease (RRD). And while Knock Out roses are its most famous victims, the disease is a threat to all commercial hybrid roses, including favorites such as hybrid tea roses, floribundas, grandifloras and old-fashioned varieties.
The organism for RRD is an eriophyid mite – wingless and microscopic – carried on the wind, which means mass plantings are particularly susceptible.
“It spreads like wildfire when they’re planted close to each other,” said a local horticulturist. “The mites seem to be most active in late summer, but damage won’t manifest itself until many months later.”
The best tip given, backed up by research according to reports, is to be vigilant and remove any infected plants. “Rip it out and burn it or trash it in a way it can’t contaminate the rest of the world,” said a local professional gardener.
Horticulturists at the Fort Worth Botanic Garden provided this information about the virus:
•    This virus infects only roses and cannot survive outside a living rose bush.
•    A tiny, invisible mite transmits the virus from an infected bush to a healthy bush. The mite cannot fly and cannot crawl very far, but it can be carried by the wind. In fact, the wind can carry the mite for miles, putting the roses of other property owners at risk when infected bushes are not removed quickly.
•    Symptoms of the virus include witches’ broom (proliferation of distorted, terminal growth), excessive thorns on the stems, malformation of leaves, excessive shoot growth and plant death.
•    There is no cure for this disease. Pruning the diseased branches will not save the infected rose bush, and keeping the infected bush in place only perpetuates the disease.
•    Once a rose has been infected with this virus, the entire plant, including the roots, should be removed immediately. Before digging up the rose bush, place a bag over it to trap the mites, dig it and then dispose of it. Do not put infected roses in your compost pile.
•    Leave the hole vacant for one week, then replant with another rose bush if you wish. (The virus does not contaminate the soil.) Otherwise, replace with another shrub or perennials.