The City of Allentown Parks Department is battling Rose Rosette Disease or RRD at the Allentown Rose Garden in Cedar Creek Parkway.
The department is currently working to remove and replace more than half of the Rose Garden due to the disease.
What Rose Garden maintenance staff believed to be Rose Rosette was discovered last August, toward the end of the growing season. That was finally confirmed last month when root and shoot samples were taken from roses and sent to the Plant Disease and Insect Diagnostic Lab (PDIDL) at Oklahoma State University. On February 25, the city received the results that the samples indeed tested positive for RRD. Previous tests done by Penn State Plant Disease in January had proven inconclusive.
It is the first known outbreak of Rose Rosette in the area.
The city is removing the infected beds. More than 700 roses are being removed and replaced with some 450 roses spaced out on 2-foot-to-4-foot centers based on variety. Once removed, city crews will then excavate anywhere from 6-to-9-inches of soil per bed to remove the entire root system from the plants that had been infected. The ground will be replaced with a very well-drained soil mixture and the beds will then be ready to be planted. The city hopes to have the Rose Garden replanted by mid-spring.
According to an article in Texas A&M AgriLife, “Rose Rosette is a disease that only affects roses and is caused by the Rose Rosette Virus (RRV). The virus gets transmitted from plant-to-plant by an eriophyid mite which can be moved around by the wind, on clothing or by traveling from plant to plant if they are touching. There are many symptoms of RRD which include witches brooms, leaf discoloration (usually bright red) and shoots or canes larger than that of the parent shoot. Roses that show signs or symptoms of this disease need to be removed immediately to prevent it from spreading to other plants. There is no known cure for RRD and a very limited number of roses have shown resistance to RRD.”
Replacement cost for the roses is estimated at $8,000.