A Deeper Look at Rose Rosette Disease

Back in May, I posted some pictures of some wild growth of my rose Tradescant that I called a Monster Rose. Through the help of others we identified that what was affecting my roses was Rose Rosette Disease or RRD.  RRD (Rose Rosette Disease) causes a form of growth that is a hyper frenzied growth that is sometimes referred to as Witches' Broom.  Since that time I have been on the look out for  RRD and found it this winter on the one rose that was at our home before we moved here.  It was growing in two spots on a plant of Blaze Improved.  Isn't Blaze Improved what people grew before Knock Out?

It is believed that RRD is transmitted from one affected plant to another through a wingless mite which chews on an RRD affected plant and then is blown by the wind to a plant that becomes affected when the mite chews on the second plant.  The most complete information of RRD is found at Ann Peck's site  http://www.rosegeek.com/ .  I encourage you to read her site to understand just how pervasive Rose Rosette Disease is becoming.  One interesting feature of the growth is that generally as a branch grows further out the growth becomes smaller.  On a RRD affected plant the growth seems to get larger and sends out more growth than can be sustained.  I have pulled off some of the leaves so you can see exactly what I am talking about.

From the Spring I had three affected plants: Tradescant, Buff Beauty, and Lavender Lassie.  I was not willing to give up on these plants and follow the advice given - to dig up and throw out the affected plants.   So I cut off all the affected areas in an attempt to save the plants.  Of the three I lost both Tradescant and Buff Beauty.  So far it looks like Lavender Lassie will be saved.  Below is a picture of the last part of Tradescant that was dug out and thrown away.  I continually cut the plant back to just find more growth the next time I went out to see the plant.

Through my experience this year, I have been on the look out and what I have seen alarms me.  I found affected roses among my mother's roses, in the Oklahoma City Will Roger's Rose Garden, and in the Tulsa Municipal Rose Garden.  I have seen it everywhere.  After my experience this past year, I have some suggestions for how you might deal with this when you find it on one of your plants. If the plant is widely affected - get rid of it.  If however, you find a small amount of RRD growth on the end of a cane - cut off the cane as far back as you can possible make yourself.  This is the best hope of saving the plant.  It is hard when you have plants that you have been waiting to get to full size but it is better than starting over with a small band.  Radical surgery sometimes is the only thing that will save a life.  One other suggestion,  when you find growth on one of your plants, as soon as you can take several cutting from unaffected portions of the plant and see if you can get a replacement plant started in case you can not save it.

I know this is not a cheery post, but I hope that you will find this information helpful should you see anything like this in your garden.  And from what I have seen, I think it is only a matter of time before we all begin to see RRD in our gardens.  The one available chemical that seems to kill the offending mite is Sevin.  Maybe you should add it to your list for Santa.