“Rose rosette is an epidemic, and North Texas is the epicenter,” said David Forehand of the Dallas Arboretum: “This is a game changer for roses, I’m sad to say.” This was in a July article in the Fort Worth Star-Telegram by Sara Bahari, reflecting the anguish felt by Texans regarding the demise of so many of their beloved rose gardens.
Fellow BYGLers Erik Draper., Pam Bennett, and Jim Chatfield were in Dallas-Fort Worth at the Fort Worth Botanic Garden this week for our pre-walkabout before for annual Tree Diagnostic Workshop that we do for the International Society of Arboriculture. We noted something peculiar about the fabled Fort Worth Arboretum rose gardens, fabled as in on the National Registry of Historic Places. Fabled as in the fact that in the 1940s, half the roses produced in the United States were within a 10 mile radius in north Texas of Tyler. Yet, yet, in this rose garden: NO ROSES.
It is a sign of the times: rose rosette virus, a plant pathogen vectored by a microscopic, eriophyid mites (Phyllocoptes fructiphilus), has resulted in roses here being replaced by beds of hibiscus (look sort of like roses from afar) and purple fountain grass and blue phlox. As local rosarian and arboretum gardener Tim Henson, noted:
“Stems covered with thorns. Leaves crinkled and puckered. Deformed buds with multiple shoots that turn a hue of red. [variable on different rose taxa} You plant a bush and four months later have to rip it out. The disease is everywhere.”
Also noted in the Star-Telegram article: “Southlake is removing and replacing more than 5,400 rosebushes in medians and parks because of the disease. Costs could reach $500,000, city officials have said.”
What to do? We do not have virusides and the mite vectors are very difficult to control with miticides. The strategy they have adopted, noted by another Fort Worth Botanic Gardens horticulturist we talked to the next day was: the removal, destruction and disposal (already accomplished) of the systemically infected roses (including the roots), hoping to reduce populations of mites over the next months, then replanting, modestly, with roses intermingled with other plants. As the Texas rosarians noted: “All of these rosebushes planted together creates an interstate highway for the mites…They can have a field day.”
Certainly this is a new way to look at rose gardens for many rosarians – no monocultures! And the problem a number of years in the making and certainly severe as well here in Ohio, though perhaps not as cataclysmic as that described here in north Texas.