From time to time, a “new” plant disease seems to get a foothold and persistently wreak havoc in landscapes. A discussion on Rose Rosette Disease (RRD) is one of those that bears repeating. Although it is not truly a new disease, RRD is new for us.
To date, Ector County is as far west in Texas that RRD has been confirmed in tissue samples.
Rose Rosette is almost always fatal to roses. A few bushes have the virus without the symptoms in College Station. However, most roses that test positive will usually succumb to the disease it in short order.
The virus is transmitted by a microscopic mite. When an infected mite feeds on tender new growth, it will simultaneously release the virus into the plant. As far as researchers know, RRD only kills roses. Other plants related to roses such as peaches, hawthorns and strawberries, are not at risk.
Symptoms of RRD in roses include a profusion of purple or reddish leaves that are stunted to give the appearance of a witch’s broom or pom-pom. One of the most prominent signs of RRD is the development of excessive numbers of tightly condensed thorns along stems. Not all symptoms must be present for the disease to cause the plant to die.
There is currently no effective treatment for RRD, but ongoing research has been funded by the United States Department of Agriculture. Horticulturists often recommend that infected roses be completely covered with trash bags prior to digging them up. Follow up treatments with miticides applied to the soil and nearby roses may help keep the disease-causing mite from spreading to healthy bushes.
If you suspect your roses may have symptoms of RRD, call the Midland County Texas A&M AgriLife Extension Service at 686-4700 or email firstname.lastname@example.org.
Amie Casbeer-Texas A&M AgriLife Extension Service and Master Gardener Support Staff Member contributed to the column.