Rose Rosette and Knock Out Roses
Rose rosette disease |
Rose Rosette disease is at epidemic levels here in Tulsa and surrounding counties. It is very important that you inspect your bushes on a regular basis to find the disease and destroy the bush before the virus spreads. It is suspected that the virus can be spread by a mite and all indications are that it is readily spread when you prune an infected bush and move to the next without disinfecting you pruners. The only way to rid yourself of the problem is to destroy the bush. Removing the affected canes does not eliminate the virus.
The majority of the roses I have found during my monthly visits and calls for help with "funny looking leaves" have been Knock Out roses. In fact of the 35 or 40 roses I have found with Rosette disease only about 2% have been something other than a Knock Out and in many cases the other variety with the disease was planted next to or in close proximity to a diseased Knock Out. As a rule I never dead head Knock Out roses. I prune them in the spring, disinfecting my tools between each bush. That said, I have been to locations where the Rosarian in residence has pruned or dead headed the Knock Outs without disinfecting between bushes and now have up to 50% of the bushes with the virus. The virus does ultimately kill the bushes but not before spreading rampant through the rose garden.
I have found myself and read multiple accounts of Knock Outs with the rosette virus that I called the company that introduced the Knock Outs and left some information about my findings and asked to be called back to discuss the problems further. I never received a call back.
Years ago rosette virus was being spread all over the United states when producers were using untested multiflora root stock as the root stock for many of their varieties. The multiflora rose is known to be able to carry Rose Rosette without it being fatal to that species. The push to eradicate the virus was started and all multiflora stock was quarantined until it was free of the virus. The remaining stock was said to be indexed and available for use.
There are hundreds of thousands of Knock Out Rose bushes planted in the United States. This is the 10th year of their distribution and as they have become more prevalent in the landscape many of them are exhibiting varying levels of disease. I am not telling anyone that they should not have Knock Out roses in their garden I am just suggesting that you inspect them carefully and often for signs of Rose Rosette and destroy them at once should they be infested.
As always should you have questions or concerns do not hesitate to call me here at Roses inc. Tulsa.