Wednesday, July 13, 2011

They Say That Bad Luck Comes In Threes

(Dec. 13, 2012.  This post is getting a ton of hits right now.  I'm glad to see it, because it means that there are folks out there who want to know more about Rose Rosette Disease.  Please do me a favor and leave a comment to let me know how and where you found this post.  Thanks!)

Over the past couple of weeks, I have found Rose Rosette Disease on three of my roses.  Never heard of this, you say?  Most people haven't, so don't feel bad.

Rose Rosette Disease (abbreviated RRD) is a virus, or virus-like, disease of roses that is transmitted by an almost microscopic wingless mite and it is almost always fatal.  It is important that rose growers be aware of the symptoms, and be prepared to take action should the disease affect one of their roses.

I first found RRD symptoms on "Miriam's Pink Powderpuff", a hybrid perpetual rose that I am very fond of.

Abnormal new growth, hugely hyper-thorny, with stunted flower bud.

Deformed flower and an unbelievably, abnormally thorny stem.

Normal new growth on "Miriam's Pink Powderpuff" should look like this.

RRD causes new growth to be unusually large, abnormally thorny, grotesquely concentrated and contorted.  The red color can also be an indicator, but don't use this as an absolute sign because many roses normally have red new growth.  Symptoms are highly variable, so it is important to recognize what normal growth looks like on various types of roses.

RRD on a cane of 'Baron Girod de l'Ain'

RRD can cause all the growth buds at an infected node to break and grow at once.  The arrows point to places where there are three sprouts from each node.  This contributes to the concentrated nature of the Witch's Broom growth.

This tiny new sprout on an infected cane clearly shows that there are three new stems coming from one growth point ... not a normal situation for 'Baron Girod de l'Ain'.

This is what healthy new growth on the Baron should look like.  The new leaves are bronze red, and they quickly turn green.  The stems are thorny, but not hyper-thorny and menacing like the canes with RRD.

This morning while I was working in the Rose Field, I saw this in my row of modern shrub roses.

Witch's Broom growth on 'Gentle Persuasion'

As I pulled aside the weeds, the full extent of the contorted nature of this cane was obvious.

RRD on this rose has caused abnormally concentrated, thorny growth and deformed flower buds.

Normal new growth on 'Gentle Persuasion' is much more mannerly ...

... and the buds are a lovely butter yellow.

There is no cure for RRD.  If the disease is noticed early, while there are symptoms on only one cane of the rose, you may be able to save the plant if you remove the entire affected cane ... I have saved one rose this way.  The only reason I even tried to save it is because it was a very rare rambler, and I'm one of the only people on the East Coast who grows it.  It has been a year since I removed the abnormal cane, and I have seen no sign of RRD on that rose yet.

Most of the time, the disease has already spread to other areas before you notice it, and it will show up again as soon as new growth starts.  This is what happened to "Miriam's Pink Powerpuff".  I noticed abnormal growth on her early this spring, and I removed that cane.  Now that the disease has returned, I know that it is probably throughout the plant, and I have removed the whole thing.  "Baron Girod de l'Ain' and 'Gentle Persuasion' will leave as soon as this heat wave breaks. 

The absolute best reference I know to educate yourself about Rose Rosette Disease is an e-book written by Ann Peck.  Ann is one of the country's leading authorities on RRD, and she has been studying and tracking the disease since the 1990s.  In the introduction of her book, Ann says, "I hope this book will educate rose growers so they can recognize RRD early, take the proper actions to deal with it and continue to grow roses." 

While RRD is a concern to rose growers, I will never let this prevent me from growing roses.  To put this in perspective ... I have more than 800 roses in my garden and in pots waiting to be planted, and I have had RRD in my garden a total of only six times so far.  From talking to other rose growers, conditions this year seem to be favorable for RRD transmission.  I doubt I have seen the last of it this year ... though I sure hope I have. 

RRD may mean the death of the infected rose, but it should not prevent you from growing and enjoying roses.  Get educated ... read Ann's book.

To read Ann's book, click HERE.


  1. So sorry for the loss of these beautiful Roses. I know you will grow some new one's. What an interesting but destructive disease!
    Good Luck. Linda

  2. Thanks for the info, is it something that can infect all sorts of roses, or mostly one particular variety of roses, such as ramblers or climbers? And I hate to hear about a rose dying. You've turned me in to a rose lover and I enjoy going out each morning to see what the roses I got from you have to offer. Every day it's a new treat!

    Kat :)

  3. That is heart breaking, a couple of years ago, I found RRD on one of my roses, and I trimmed it hard, and I must have caught it early. Thanks for the reference, going to put that in my favorites. Donna

  4. So sorry to hear this. It must be heartbreaking to see it on a beloved rose. I'm glad you did a post on this. I don't think many rose growers know about it, and they should.

  5. Oh Connie, I hope that's the end of it for you!

  6. Oh my goodness, a virus? Never heard such a thing. Those photos are amazing, even if the roses are sick. They show exactly what you are explaining.

  7. That is really really strange stuff right there. Never seen it before.

  8. So sorry to hear about the RRD in your garden. We have that creepy RRD all over the place in the pasture roses up here. I took out the roses I had planted right next to the road because I read that RRD often spreads fastest by the roadside and railways because the cars driving by create a breeze that moves the mites to the next rose faster. I sure hope we find a solution to RRD. There is something so special about roses and it is heartbreaking to lose them to a hideous disease like that.


  9. Wow! I really learned a lot about this! Even if I do not grow roses, I love educational posts!
    I do hope this is the last of it for you...
    The butter-colored rose is amazing!

  10. Oh, Connie, I can only imagine your gasp when you came upon that witches' broom on 'Gentle Persuasion'. What a horrible thing! I'm so glad RRD's not in Florida - at this time anyway. I don't think Multiflora is very plentiful here - at least I hope it isn't. It's not good for rootstock anyway.

  11. Fingers and Toes crossed that it stays "contained" to VERY few of your lovely roses.
    I'd never heard of RRD, thanks for the education. It would be awful to let it spread because I didn't know any better!

  12. thanks for this information. I am sharing with others....


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