Since this is such a hot topic right now, it would be a good idea to call into the radio program on Sunday morning to ask Howard himself. I'll paste in a remark that Howard added to the Library of Organic Information back in March:
Quote:
In checking back with some of the people that have had success with the rose rosette control, I've found that the reports are mostly positive although somewhat mixed. Many gardeners are still having successful control but others are reporting the disease coming back with a vengeance. It's apparent from talking to these people that very few of them are using the entire program that we recommend. One reported failure didn't even have the hydrogen peroxide in the spray. That's one of the problems asking homeowners to help with this research. Although I'll continue to recommend the solution and use it myself, my amended position is now this.
For the successful treatment of rose rosette, proper pruning and the entire Sick Tree Treatment must be used with the addition of hydrogen peroxide to be 1% of the spray solution. For help with the vector mite that helps spread the disease, add orange oil, spinosad or an essential oil product to the spray. If the disease returns after this complete treatment or if roses are severely infested at the onset, I admit that they should be removed. Replanting roses still remains debatable, but should probably only be done if 100% of the roots of sick plants are removed. Knock Out roses should cease being used while this disease continues to be rampant.
Here is his
Rose Rosette newsletter with his full formula.
Good luck with this.