Roses suffer from rosette virus

Tyler—There are currently more cases of rose rosette virus in Tyler than at any point over the ten years that I’ve worked here. Tyler is known as the “Rose Capital of America,” so not growing roses isn’t an option. That’s why it is critical to recognize this devastating virus and remove the plants when symptoms appear.

The symptoms of rose rosette are distinctive. The most obvious sign is a bizarre, densely clustered growth at the ends of branches known as a “witches’ broom.” These shoots often display an unusual red-orange color and an excessive number of thorns. However, color alone isn’t conclusive since many roses naturally produce new burgundy growth. Infected plants often look like they’ve been hit with a broadleaf herbicide. You might also notice flattened or unusually elongated stems, distorted leaves, and rampant, erratic growth. In early stages, symptoms may appear on just a few shoots, but the disease spreads internally and eventually weakens or kills the plant over time.

Rose rosette virus spreads in two primary ways. In the garden, it is transmitted by a microscopic eriophyid mite that feeds on infected roses and then moves to healthy ones. These mites are so small that wind can carry them from plant to plant. To reduce the chances of spreading, avoid letting roses touch one another. The virus can also be transmitted through propagation. Any rose grown from cuttings or budwood taken from an infected plant will carry the disease since the virus lives within the plant’s tissue.

There is no cure. Pruning away the affected growth will not remove the virus, and applying pesticides or homemade remedies will not help. Once symptoms are visible, the disease has already spread throughout the plant.

The only solution is to remove and destroy the entire rose bush, including its main roots as soon as symptoms are detected. Seal the infected plant in a trash bag and dispose of it with household waste or burn it if local regulations permit. Leaving infected roses in place puts all your other roses, and those across Tyler and East Texas, at risk. The virus is not soilborne, so once the diseased plants are gone, healthy roses can safely be replanted in the same location, although I’d suggest waiting until fall, winter, or spring when conditions are mild and moist.

If you suspect you have rose rosette, but are not certain, you may submit a sample to the Texas A&M AgriLife Extension Plant Disease Diagnostic Laboratory in College Station. Instructions and submission forms are available online at plantclinic.tamu.edu. There is a fee for diagnostic testing.

Greg Grant, Ph.D., is the Smith County horticulturist and Master Gardener coordinator for the Texas A&M AgriLife Extension Service in Tyler.