Roses have been a beautiful and fragrant part of our garden palette for thousands of years. Humans have cultivated roses for their medicinal properties, for the floral trade, and for beautifying our public and private gardens. Through breeding, we have increased the flower petal count from the typical number of five on a species rose to sometimes more than a hundred. In addition to boosting the number of petals, roses have been bred to flower repeatedly rather than just once a growing season, typical of most species roses. Rose breeders have also bred for size, color, fragrance. Over the last couple of decades they have made breeding for resistance to fungal diseases a priority. All of these many characteristics have made it possible to find a rose to fit most of our desires and even to garden more responsibly by relying less on fungicides. This is good news!

However, I do have some bad news. The bad news is that there is a disease called rose rosette disease (RRD) caused by the rose rosette emaravirus (RRV) that is harming some rose gardens. First described in the 1940s in the western part of North America, it has made its way to the East Coast. According to roserosette.org, there are only a few U.S. states that have no reported cases of RRD.

Symptoms include:

  • Shoot proliferation (sometimes called “witches’ broom”)
  • Excess thorns
  • Enhanced red shoot coloration
  • Leaf distortion/strappy thin leaves
  • Flower distortion
  • Poor plant growth (yellowing or stunted growth and branch or shoot dieback)
  • Plant death

The virus is spread by tiny eriophyid mites which travel on wind currents. Keep a close eye on your roses… and your neighbors’. The current recommendation is to bag and remove any infected plant(s) as well as their roots. For more information on control visit https://roserosette.org/

Now back to breeding roses for specific desired traits…

Good news, there is research underway now to screen the genetic material in roses for potential sources of RRD resistance. For a deep dive you can read the article “Field Resistance to Rose Rosette Disease as Determined by Multi-Year Evaluations in Tennessee and Delaware” published in Pathogens in 2023.

If you discover that your rose has Rose Rosette disease, I understand your disappointment as I have had to remove more than a dozen plants from the Kathrine Dulin Folger Rose Garden over the last three years. Try, as I have, to see this as an opportunity to improve your garden and keep looking through your rose-colored glasses.