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ingrid_vc

Many of My Roses Have Canker

I had noticed that a miniature rose, which I've had the longest of all my roses, had begun to decline over the last year or two. It had always been a bloom machine so I couldn't understand what was wrong. Today I took a good look underneath and noticed thick, shaggy canes near the bottom, one of which looked at though it had a split in it. At first I thought crown gall but, after a lot of researching, realized it was canker. Looking at nearby roses, I saw purple splotches further up on the canes which looked exactly like the pictures I was seeing of canker. Walking around the garden, I began to see more and more examples. My husband dug out the miniature and that will go in the trash and the soil will be discarded. La France, one of my very favorite roses, I cut down to the nubbins but left in. I pruned another La France and Marie Pavie, which were closest to the miniature and which also showed symptoms.

With bilateral torn rotator cuffs, fibromyalgia and back and hip problems, I feel as though this is a very dire situation. My question is whether it's a given that all my roses will be infected. I know about removing all the soil, sterilizing pruners etc. I'm reluctant to use a fungicide given the precarious status of the insects and wildlife during this drought. Their numbers have already drastically decreased. I cannot take out every infected rose, it's beyond my abilities, and I doubt that at this point I have the ability to start over again.

Any comments and advice are appreciated.

Ingrid

Comments (34)

  • jacqueline9CA
    9 years ago
    last modified: 9 years ago

    Ingrid - all I can tell you is that I had an infesation of canker also, about 3-4 years ago. We lost 3 giant roses (Le Vesuve - which went from healthy to dead in a month! -, a huge old Cecile Brunner, and an ancient Duchesse de Brabant). It showed up on some other roses also. We dug out the 90% dead ones, and did replace the soil in an area about 10 ft by 10ft.

    I saw symptoms on other roses, but not so bad. Those I just pruned off every cane that had symptoms, and did spray with a fungicide (without any pesticide in it - I HATE those "2 or 3 in one" products!) which specifically said it was for canker. We did not lose any other roses. I kept an eye on the ones which had had symptoms. On one Madame Alfred Carriere (luckily a young one) two more canes got symptoms months later, but I did the same thing, and it has been canker free now for over two years.

    I have not seen signs of canker anywhere else on my 140+ roses, either. I have the impression that if you jump on it quickly, you can fight it off. If I were you I would seriously look into using a specific canker killing fungicide, not all over but just for the roses where you have pruned off infected canes.

    Jackie

  • buford
    9 years ago
    last modified: 9 years ago

    I normally get some canker each winter, I just prune it off. However, last year is was very bad, probably due to our very cold winter. Some roses just could not over come it. I even had roses I bought that succumbed while still in the pot. I usually just cut what I can and then apply a fungicide.

    It could be that drought stress has made your roses susceptible. Canker is something that seems to prey on weak roses. Is there a fungicide that you could apply topically with a brush so you wouldn't have spray all over?

  • ingrid_vc so. CA zone 9
    Original Author
    9 years ago
    last modified: 9 years ago

    Thank you for your help. Jackie, could you please recommend a fungicide? I looked on Amazon and there were so many my head was spinning. Lots of 3 in 1 products and nothing I could see that was specific for canker, but I haven't studied this carefully. I hope you'll have suggestions, or for that matter I'd like to hear from anyone who happens to read this.

    Since I began this thread Lady Alice Stanley, La France, Mme. Cornelissen and Marie Pavie have been earmarked for removal, in addition to the rose I've already taken out. Of the two La France, I had to cut one back all the way to the surface to get rid of the bad canes, and I don't know if it's worth salvaging. I cut into the canes on all these roses and the pith was either yellow or yellow on the outside, with still a white area in the middle. On some the young growth had white cut surfaces but the canes further down were yellow-brownish. I don't see how any good can come from keeping those plants.

    buford, I have no doubt that the drought stressed these roses, but as you say these were the smaller, weaker roses and I only wish I had studied them more carefully. Frankly, canker never entered my mind. It seems I still have a lot to learn.

    Ingrid

  • buford
    9 years ago
    last modified: 9 years ago

    I'm wondering if one of the organic fungicides would work on canker, like copper or sulfur. But if it's that bad, you may want to go with something stronger.

  • titian1 10b Sydney
    9 years ago
    last modified: 9 years ago

    Hi Ingrid,

    So sorry to hear you have yet another problem. I'd never even heard of canker, but have a horrible suspicion some of my roses have it. Too hot now to go and look.

    Here is some info I found. Hope it helps.

    CANKER

    Canker is a garbage-can term for several fungal diseases that attack the stems or leaves of roses.
    What these all have in common is the presence of dark spots or lesions that grow and kill the plant. They can all be treated in a similar way.

    Fungus: Coniothyrium wernsdorfiae also known as Brand Canker

    The green bark of the previous years stems develops reddish brown or purplish black oval shaped spots or lesions. These later turn brown and spread down the cane as the disease develops. The stems will collapse and die unless it is dealt with. Sometimes you can see this disease in your local nursery. Don't buy a plant infected with this scourge unless it is on just one or two canes that can easily be pruned off without major damage to the overall plant size. Most common in the garden, in spring and again in late summer. This fungus enters through mechanical wounds in the bark or frost damage of canes. Some varieties of rose are more susceptible than others. Heavy applications of wet manure or compost left too long on the plants in the spring can contribute to this problem.
    Treatment:
    The ONLY treatment is to cut off the cane below the infection and remove it from the garden. If any is left, it can reinfect the entire bush, so you must get it all. Make sure that you dip your pruning shears after every cut, in a bucket of 1:4 mixture of household bleach and water. You do not want to spread the disease with your pruners. Chemical controls are mostly ineffective for these canker diseases. All of the 'Canker' afflictions can be treated in this manner.

    Fungus: Coniothyrium f'kelii or Leptosphaeria coniothyrium also known as Stem Canker F'kelii.....that's pretty funny.... heh heh...
    That IS what it does to your rosebushes metaphorically speaking.
    The symptoms are large irregularly shaped lesions. Usually parched brown discoloration is noticed on the canes. They are sunken near the edges and swollen in the middle. The surface or edges may become wrinkled and then rupture, releasing spores. Canker ususally enters through a mechanical wound in the bark of the canes. This disease if left unchecked can kill a rose, especially if it is a one or two year old bush that is not yet fully established, OR an old less than healthy bush or climber. The stems will turn black and die from top to bottom.
    Treatment:
    The canes MUST be cut off below the infected portions on all of the canes. If the infection reaches the bud union, the rose will die. Remove the cut off infected wood from the garden and sterilize your pruning shears after cutting the damaged canes as this disease is easily spreadable. When pruning DON'T leave long stems above the last bud, as the disease favors attacking the rose at these points. Cut 1/4 inch above the bud at an angle only. Chemical controls for stem canker are not known.

    Fungus: Cylindrocladium scoparium also knows as Crown Canker or Cylindrocladium
    Plants are usually attacked at the budding point. Discoloration of the bark which spreads slowly to very rapidly, to encircle the whole stem. Once the stem is encircled, the plant weakens and dies. This is more of a problem in newly budded plants. And is seen in nurseries more than in the garden.
    Treatment:
    Cut off and discard the infected plant parts outside of the garden.

    Fungus: Septoria rosae also known as Leaf Scorch Irregular blackish spots with reddish or purple edges 3 to 12 mm in diameter. These spots develop on the leaves.
    Treatment:
    Cut off and discard the infected plant parts outside of the garden.

    Fungus: Gnomonia rubi
    Large brown spots with purple edges. Yellowing and die back of the stems. Infection in spring on frost damaged buds. Possible connection of spreading from blackberries.
    Treatment:
    Cut off bad stems and discard out of garden.

    Fungus: Diplodia rosarum also known as Die Back Dark spots appear on stems and rootstalks.
    Treatment: Same treatment as all of the other cankers. Cut and discard. Dip pruners after each cut in water with bleach in order to not spread the disease.

    Good luck.

    Trish.

  • nanadollZ7 SWIdaho
    9 years ago
    last modified: 9 years ago

    I'm so sorry that you have this problem in your garden, Ingrid. I've had a little experience with various blight and canker on my roses. Several years ago it really hit, and I found that, for me, anyway, spraying was not necessary. After pruning out the worst of the bad canes, and being meticulous about using 70 percent alcohol on the pruners after each cut, I was able to leave the less severely affected canes to sink or swim, and swim they did. As the weather warmed and it dried out, the remaining canker disappeared on those less affected canes. I didn't lose a rose. I found that by pruning later in the season when it was warmer, and always using alcohol between each cut really cut down on any infections. By the way, some canker is bacterial, and is called bacterial cane blight.
    If you want to spray, you can use Daconil, Immunox, or Funginex. You can also dust with sulfur, according to what I've been reading.
    Diane

  • mariannese
    9 years ago
    last modified: 9 years ago

    I think stem canker is a mysterious disease. I had it on several roses about 10 years ago but at first I didn't understand what it was until a friend told me. It was hardly ever mentioned in older Swedish rose books. After I lost a large Constance Spry I became more observant and cut stems way beyond purple spots as soon as I noticed them.

    Over here where we usually winter cover our roses it is said that wet covering such as leaves or mulch may contribute to the disease but that is hardly the case in California. I have stopped winter covering and haven't had canker for several years now. I don't know if that is the reason or if the disease is less rampant at present.

  • jacqueline9CA
    9 years ago
    last modified: 9 years ago

    Ingrid - of course it is true that the term "canker" is a vague term. Mine turned out to look really a lot like downey mildew. The fungicide I used was "Agri-fos Systemic Fungicide" (although the instructions say you can spray it too).

    All I know is that the problem went away, and when I see any symptoms, I cut off and canes which are showing them and spray with this stuff, and it works. Of course, it could certainly be that it is just a coincidence, and the disease left on its own (I am not being sarcastic - sometimes diseases do that!).

    Jackie

  • mustbnuts zone 9 sunset 9
    9 years ago
    last modified: 9 years ago

    I am so sorry to hear you are having such issues with your roses. Seems like it is always something, heat, water, animals, etc. So not fair when you have such a beautiful yard and are always willing to help everyone.

    If I was closer to you, I would give you some cuttings from my yard to help replace any roses you may lose. I will keep my fingers crossed that all will be well with the suggestions you get on here.

  • nanadollZ7 SWIdaho
    9 years ago
    last modified: 9 years ago

    I do think canker does "leave on it own", if it's not too severe. It's not the canker leaving on its own, but the rose's immune system fighting off the infection. It's happened many times for my roses when it warms up and is dry. Diane

  • saldut
    9 years ago
    last modified: 9 years ago

    Abt. 4-5 years ago, I got canker on my roses, it had been a cool, rainy spell and I pruned w/o sterilizing my clippers .....I had never seen this before but soon learned! I lost quite a few roses and had to cut back more, but have not had a problem since...knock on wood.....now I make sure my clippers are sterile, I carry a can of alcohol and dip after each clip...just pure alcohol, the cheap rubbing kind.... also, I don't prune when it's cold and wet, as this seems to spread-encourage canker.......hope this helps, sally

  • mendocino_rose
    9 years ago
    last modified: 9 years ago

    Ingrid, I am really distressed that you have this problem. I've seen it before here, I'm surprised that it is happening in your climate. We see this is our very wet winters. It could be that cutting the diseased canes will be the answer. I hate spraying. There is a product specifically for Downy Mildew(if it is) called Aliette. There is a systemic copper product called Phyton. Systemic means it gets right into the canes. I've used it before in bad winters. I know you don't like the idea of spraying and I don't blame you. I hope these problems will resolve. You've been through enough.

  • ingrid_vc so. CA zone 9
    Original Author
    9 years ago
    last modified: 9 years ago

    When I came home from work today and walked by Bermuda Kathleen, which of course is on its own roots, I was dumbfounded to find a thick cane infected with canker that had huge leaves, with some of these large leaves growing out from the top on thin canes that encircled the large cane like a broom. None of the other roses have had this appearance.

    So far nine roses have been dug up. La France and Mme. Cornelissen had almost no roots and I don't know how they survived this long. I'm not sure if I have more than one kind of canker since I have seen the lesions on the canes but in most of the roses the problem was at the very bottom also so that the roses couldn't be saved. I spotted one bad cane on Aunt Margy's Rose and cut it off after sterilizing the clippers with alcohol (had no bleach).

    Thank you all so much for your help and kindness. You can't know how much that means to me. Your comments have taught me a lot and I feel much better about the whole situation now with your support. I'm not giving up and will be buying a few more roses to fill some of those empty spots after putting in new soil. Life without roses would be a pitiful thing.

    Ingrid

  • nippstress - zone 5 Nebraska
    9 years ago
    last modified: 9 years ago

    Oh how heartbreaking, Ingrid. After all you've had to deal with this year in the extreme drought, then you finally get some rain and then the canker hits. It sounds like La France and Mme. C. were doomed no matter what, if their root systems couldn't recover. Given that, it may be that the canker is more of a symptom than the cause of the problem, perhaps, if other roses have such weakened root systems after what they've been through.

    FWIW, canker is an expected evil for us in cold zones after virtually any winter, particularly one like this one with odd temperature swings into unseasonably warm stretches followed by bitter cold. I have frequently pruned cankered stems down entirely to the ground, and still seen affected stem below that I can't get to. Sometimes the roses shrug it off and come back, and sometimes there doesn't seem to be anything I can do to resurrect things. All you can do is give it a try for any that aren't already on their way out - at least canker isn't something that would adversely affect the next roses that you would plant in the spot.

    By all means don't give up and every closed door on a rose is an opportunity to buy a new one that catches your eye.

    Cynthia

  • ingrid_vc so. CA zone 9
    Original Author
    9 years ago
    last modified: 9 years ago

    Cynthia, with your and everyone else's support I'm using this experience as something to learn from and not to despair about. I still have 50 roses left to love and hope to add a few more in the coming days, and there is still spring to look forward to. The fact that it's raining right now is also helping to brighten my mood.

    I'll be buying 5-gallon roses with thick canes and they will be blooming this spring. It will all be fine. Thank you for your comforting words.

    Ingrid

  • mariannese
    9 years ago
    last modified: 9 years ago

    I have to chime in again. I don't think canker is necessarily fatal even though it can weaken the plant. But cutting away everything below the purple spots has worked for me when I've noticed them in time. I think I have saved my old climber Flammentanz, perhaps planted in the late 50'ies, that was in the garden before I came here more than 20 years ago. Of course, I don't know if American strains of canker are different from what we see here.

  • ingrid_vc so. CA zone 9
    Original Author
    9 years ago
    last modified: 9 years ago

    Marianne, never before having seen canker in all my years of gardening with roses I wasn't aware of what to look for and I think that's why some roses that hadn't done well for some years like own-root hybrid teas had canker without me being aware of it. Once I started cutting into the canes I had to keep going further and further until nothing was left, and I didn't think these weaklings would ever make a comeback, especially since the roots were so wimpy. My only real regret is La France, and perhaps some day I'll try it again.

    Ingrid

  • ingrid_vc so. CA zone 9
    Original Author
    9 years ago
    last modified: 9 years ago

    vasue, thank you from the heart for your wonderful post, although I'm not sure I deserve everything you say. I appreciate all your practical comments, and I've learned quite a lot on this thread. What I appreciate most is the encouragement that this event is not a tragedy, just a little stumble along the road, something we all experience in gardening, as in all of life. I've already chosen the new roses I'm going to plant and want to get them in the ground while it's still cool. It's going to be a good spring!

    Ingrid

  • Brian
    8 years ago

    I've decided to add to this post to say that I all of a sudden have this in my rose garden! I would guess about 13 of my 130+ roses have this and I feel so upset. I think that there is a chance that I'm going to lose my Evelyn & Claire Rose which were large and beautiful. They have burnt looking splotches all along their canes down to the bud union. Most of other roses just have one cane that has the diseased splotch. I barely saw them this evening right before the sun went down and I won't be home until late tomorrow. I won't even be able to start any kind of remedy until Friday afternoon and now feel frustrated and hope nothing will get worst between now & the next 2 days. I have both Phyton27 and Agris-Fos, which one should I try first? Would it be bad to just use both products at the same time or a day between each?


    Thanks,


    Brian

  • plectrudis (Zone 8b Central TX)
    8 years ago

    Hi Brian--if it's a rose you love, do take cuttings ASAP. We lost a huge found rose to a hideous, aggressive, weaponized form of canker seven or so years ago, but her babies live on in our garden. If you can find a patch of stem that's fairly removed from the necrotic bits, then it's not too late.

    FWIW, we used Immunox. It helped, I guess, maybe, on some of the shrubs that just had a touch of the disease. But It couldn't save Maggie, Spice, or one of our Belinda's Dreams. RIP. The thing that helped most was winter. Whatever nasty little organism was responsible, it died in the cold.

    Other than that, our experience was that you should prune ruthlessly at the first sign of trouble, and drench the plant with chemicals after. This seems to have worked on our mild cases, but we never figured out how to save more advanced cases.

  • titian1 10b Sydney
    8 years ago

    As I've said in other posts, I have discovered almost all my roses have canker, and in all the ones I've investigated thoroughly, it's down to the graft. I've removed 13 or so that were doing really badly, and pruned the others with varying degrees of ruthlessness.

    I've been particularly ruthless with Crepescule, removing 3 of 5 thick canes, all of which were almost completely dead, and pruning the rest hard. Amazingly, it is now a mass of new growth. I keep thinking of a phrase Jackie used when I look at it - "Growth follows the cut".

    I don't know what the long term outcome will be, but I'm enjoying it for now!

    Trish

  • ingrid_vc so. CA zone 9
    Original Author
    8 years ago

    Brian, I'm so sorry that you're also having to deal with this problem. I hope that most of your roses will stay healthy, but I know that losing even one beloved, thriving rose is devastating. I hope plectrudis' suggestions will help stave of further problems in your garden. I'm keeping my fingers crossed for you. In my case I suspect the ongoing drought weakened the roses and the less robust ones didn't have the resources to fight off the disease process.

    Trish, my heart goes out to you. I know firsthand how dismal a garden can look when the sick roses are removed, although fortunately you have many more roses than I do. I still have quite a few roses afflicted with canker, but my concerted efforts to make sure the roses have enough water seem to have paid off in halting the disease process. I'm delighted that your Crepuscule bounced back. The more vigorous roses do seem to have the ability to recover from disease much more easily. Good luck to both of you.

  • titian1 10b Sydney
    8 years ago

    Thanks, Ingrid. I'm hopeful, but am now resigned also. If they all grow backwards, I shall just have to have a garden of trees, shrubs and perennials. Life could be worse!

    It is raining hard here - we generally get flood or drought, and I've read that that is stressful to the roses too. Probably I didn't water them enough in the dry periods, as I thought the clay soil would be holding enough water for them.

    Here is a photo of Crepescule taken just now in a break in the rain, with all its new growth. Not so clear is the new growth coming from near the bottom of the thick canes, which is amazingly plentiful. On the left near the top is the perennial wallflower I mentioned before. It opens yellow for a very short time, then goes mauve.


  • ingrid_vc so. CA zone 9
    Original Author
    8 years ago
    last modified: 8 years ago

    Trish, this rose is doing its best to come back, breaking out everywhere with new shoots. The rain will encourage your roses to grow and if you can keep them well watered all the time I think you'll see lots of improvement. I wish I had done this years ago, because I can't tell you how beneficial the drip system we put in has been for all the roses, old and young. If you can manage something similar, I think you'll see the same dramatic improvement I have. Putting it together the way we did is very simple and now I'm loving not to have to hand-water so much, and the roses and other plants are growing much, much better than with watering with a hose. Your wallflowers are gorgeous, that is one of my favorite colors. They really make an impact grown together like that. I'm thinking I should try them too.

  • vasue VA
    8 years ago
    last modified: 8 years ago

    Brian, are you sure that what you're seeing is actually canker? Your description of "burnt looking splotches all along their canes down to the bud union" may be due to other causes, such as sun or wind burn or concentrated sun/heat reflected from glass, water, concrete, masonry or stone. Could you post some photos of the canes to aid a diagnosis?

  • Brian
    8 years ago

    Thank you for the kind words everyone. I was able to get home just before the sun set, so I was able to prune the worst roses down to just above the bud Union. I will try and finish pruning the rest tomorrow and will spray. I was hoping to use what I have before buying something else. Should I use phyton or agri-fos? Would you spray every rose bush in the garden or just the affected ones? The following pictures are Claire rose, Evelyn, and autumn damask. I just found out that The Squire has a large amount of the splotches that I had to remove. I don't have pictures of them but I have a feeling that Mary Rose & Country Living are the culprits that started this mess since I've never heard about cleaning your pruners in between cuts and these 2 roses have shown signs of canker for months now. So this is much my fault for not trying to figure out and prevent this situation.

  • titian1 10b Sydney
    8 years ago

    Ingrid, I don't know about a drip system - the garden is on several levels. However, it may be not too difficult - I shall at least look into it. When I water with a hose now, I put it on for 2 or 3 hours in the early morning, to give a good deep soak. But, until recently, I hand watered, mainly because it would have been so wasteful to do otherwise, as there was so much space between plants.

    That walflower (erysimum) is one plant, and I don't think it has even suckered, as I've had a good rootle around hoping to find one to plant elsewhere. It does seed a little - I've found around 4 seedlings. I got it as a cutting from a friend, so you can see it's very easy to propagate, without being invasive. It's taken about 3 years to reach a size of roughly 5' by 5'.

    Another plant I love with roses is heliotrope 'Cherry Pie". It's a pretty, pale mauve. I have it growing between 2 D de B's, and to my eye the colour combination is lovely.

    I've also just planted a couple of cistus, a prostrate one, and 'Snow White'. They have very low water requirement once established.

    So happy for you that the drip system is giving you such good results. I look forward to lots more photos.

  • nanadollZ7 SWIdaho
    8 years ago

    Hi Brian,

    When bacterial cane blight hit this area a few years ago, one of the state plant pathologists recommended phyton for this disease, which we also call cane canker. Phyton works against both fungal canker and bacterial blight, and the agri-fos is antifungal only (correct me if I'm wrong). Fungi and bacteria are two distinctly different kinds of organisms. In my garden, I only cut out the worst infected canes, and leave the rest alone. I do no spraying. When weather warms, and it is drier, the remaining canes clear up on their own. I haven't lost a rose yet. Personally, I wouldn't spray the uninfected roses, but I'm no expert. I think pruning later in the season when the weather is warmer is helpful, and always disinfect your pruners.

    Diane

  • Nor
    8 years ago

    I too have lost many roses (mostly DA) this last few weeks to canker. I am starting to see sign of canker on Clothilde Soupert and BD as well. I see a lot of dead wood on Julia Child that was hidden by underplanting, so maybe it was canker as well...The warm and wet weather is making the situation worse; 2 hours of rain yesterday alone. I promised myself not to buy anymore roses but if things doesnt look better, I might have to break my promise. Next time, no more DA! (or maybe one ONLY)

  • Brian
    8 years ago

    Even though I know that some of my roses have canker for sure, is it possible that some of this can be sunburn? I was out of town this last weekend while our temperatures in Orange County hit over 100 degrees. When I returned home I was shocked to see so many roses have these brown splotches everywhere and I went mad with pruning thinking that it was rose canker exploding in my garden. I realized today that my roses that are now in almost full shade from the sun shifting show no signs of splotches or disease which is now making me think that most of the damage on my roses is just sun burn and not Rose canker. Also most of the brown and black splotches are on the sun facing sides of the canes. The canes start out with getting light brown dots which eventually turn solid brown. Some of the worst canes are very black and appear greatly on the ends of the new soft growth of the canes. What do you guys think?


  • Brian
    8 years ago

    Here's more photos

  • henry_kuska
    8 years ago

    Plants have an immune system. Scientific research has shown that external application of immune system boosters such as salicylic acid (easy to obtain substitute - aspirin) or dilute hydrogen peroxide may be useful.

    Rather than repeat the documentation, I suggest you look at the following thread and internal links.

    http://forums2.gardenweb.com/discussions/3437585/help-is-this-caused-by-virus-or-bacteria?n=14

  • ingrid_vc so. CA zone 9
    Original Author
    8 years ago

    Brian, my roses get sunburn but I have to say it looks different from what your photographs show. It's usually very clearly delineated on the sunny side and is not patchy, but just a continuous darker area. Some of the canes you show look more like canker to me or some other disease, but I would let others comment, since I don't want to mislead you.