A type of canker. There are various pathogens that cause canker on rose canes (stems), including Botrytis, Coniothyrium, Phomopsisa, Leptosphaeria. Spots may be black, brown, purple, red; the canker may be enough to kill the cane or slightly to significantly degrade the cane's ability to produce leaves and flowers. Some species and cultivars are more vulnerable than others.

General advice for cankers include:

1. Prune out diseased branches. Prune out all
infected branches and remove them from the site. Prune in late
winter when it is sunny and the plants are dry. Dip pruning tools into a
solution of 1–part bleach and 9–parts water between cuts to reduce
spreading the disease. After pruning, oil blades to prevent rust.

2. Avoid injuries to bark and stems. Wounds can provide entry points for the pathogen, especially during wet periods.

3.Improve plant health. Water during dry periods and
aerate the soil around the plant to relieve soil compaction and
facilitate water and nutrient penetration. Fertilize to maintain vigor.

4. Maintain good air circulation. Chances of
infection are greater on plants that are crowded together. Space plants
out when planting to accommodate mature growth.

5. Bordeaux mixture or a copper-containing
fungicide may help slow the spread of the disease.

6. Remove the infected plant and plant a different species or variety.

Wow that really stinks! I'll have to go prune them tomorrow when there's daylight. Thank you so much for telling me!

I had a rose like that last summer. This was very helpful!!

Carol

My zeffy looked like this because the winter where I live is too tough for zepherine drouhin and leaves it susceptible. As the summer went on I was able to prune it out. It looks like a thornless rose.

My baby SDLM has some spots like this - I was dithering on pruning it back because it'll reduce it down to rather small but I guess losing cane is better that allowing canker to take hold. Thanks!

If it only has a few spots that don't look to be creeping and the rose is really small, I let it grow a bit before taking out the bad cane(s). That is assuming that there is good growth below the bad parts or new basals coming on! If you know the rootball is big (like top lost to winter), go on and ignore that advice, lol. But I've had some new little bands have cankers, and I let them make as many leaves as they can for a while if the canker isn't spreading (yet).

On big roses, I'm ruthless!

Funny, I have seen this on some rose canes this year and last year, but thought it was just the effects of Winter. So I didn't remove anything showing these spots, and there were no bad effects last year. This year, I first took off anything that looked dead, then anything really thin, then trimmed for shape. If stems had spots, I ignored them. As growth buds are swelling, I've done some more trimming off of bits that don't seem to be waking up. But at least on my roses, those canes with spots don't seem to be hampering vigor. Now I'm wondering about maybe getting some dormant spray on them before they leaf out.....

:-/

~Christopher

Christopher - I suspect that you may be able to get away with keeping the spotted canes because of your relatively milder climate. Here in the cold zones, we have to be a bit more ruthless early in the spring so that our roses grow only healthy canes (as much as possible) to be able to withstand the winter. As Meredith says, we also temper that for brand new roses - particularly bands, since any cane is better than none. Your roses can afford to carry a relatively weak link in some of the canes since you don't have as brutal a winter ahead of you. Still, I'd monitor them periodically to see if anything is spreading and then take actions. The spring pruning is only the first pass in my world - I'm always on constant monitoring for canker and related conditions.

Cynthia

I suspect this is another HT thing that doesn't really apply to most other types of roses. All of my gallica canes look like that in the spring, and I certainly don't prune them all out.

I know my Georgetown HP is prone to having those larger red spots grow and then the cane above gets yellow and stops putting out leaves sometime during the season or next. If the spot isn't big enough to tell what it'll do yet, I leave it alone, because some small ones really just stay and do nothing.

Those that are big right by where leaves come out (third pic above) usually mean the cane coming from there will die eventually, so I do go on and prune those out when I see them. Better to have a new cane come from somewhere else :)

H'mmm. I went out and looked at SDLM this sfternoon, couldn't get any in focus pictures, but there's only a couple of small purple ish spots on the cane in question. By small I mean 1mm to 2mm size. I'm thinking I might wait and see, particularly since there's half a dozen beginnings of flower buds on that cane.

I went out and looked at mine today, and I see those tiny red dots on quite a few roses -- not every rose, and not every cane, but on more than I'd be willing to remove. I'm just going to leave things be, and wait to see if any new growth appears wimpy before I cut anything back further. My roses came as bands in 2013, and finally this year they are large enough to put on a show. I should also add that these are mostly antiques and Austins.

:-)

~Christopher

I had to clip all my roses down to nothing, as all of them were infected to the ground (well, except for one tiny cane on each of two roses). I'm glad I did, too, because when I clipped them I saw a brown center in the canes. I could barely clip low enough to reach healthy green. Most of the roses are one year old, planted as bands last April. I think they'll do fine since the weather's warming up nicely and they have plenty of water. The only one I'm concerned about is Midas Touch, as I couldn't even reach healthy green before hitting the soil line. It had tried to put out a new cane right as winter hit, and winter hit hard. I might dig down and clip it a little lower. Any thoughts?

I'm glad my thread helped others!

..I've got some spots on my 'Kew Gardens' rose but I'm not taking any notice as it's growing away vigorously and shows no other ill effects at the moment.... these spots are spaced out all the way down to the bottom of the cane which is about 5 foot long...

You may want to clip a little off the top and see if it's all healthy green inside. I thought the spots weren't going to hurt my roses, but when I clipped them due to the advice on this thread I saw an awful lot of brown centers. In the end I'm glad I followed the advice and clipped, before it spread to the roots.

..thank you Rosecandy...yes I think I ought to do that just to see how it is....

..I cut off a piece of cane, peeled off the outer skin, and took these photos earlier today... from what I can see they look alright...the spots are very much on the outside, like a rash...

Thank you for your most comprehensive reply.... if I find any deterioration I think I shall remove the complete cane later in the summer, but for now it's doing so well I shall just monitor the situation... it's a very vigorous non-stop flowering rose, so I suspect it can outgrow this sort of thing...

Keep us posted - it's a good learning experience.

Carol

I should have made clear in my rant that the canes shown by the OP rosecandy were in bad shape owing to winter damage and did need to come out. If the red spots on them were fungus, it might have been so aggressive because the cane was injured and unable to defend itself normally. So the advice farther up to prune was correct.

However, I don't think red spots automatically call for pruning.

I'm glad I posted this thread; it's been very informative! Marlorena, please let us know how it goes this summer; it'll be good to have different comparisons between mine and yours and know what's bad and what isn't.

Welcome back from a relative GW posting hiatus, Michael! Your posts are always clear and helpful, so feel free to "rant" away. I do notice that I have to restrain myself a bit in my prune-happy state, since I'm on auto-pilot when pruning 750 roses and I can make erroneous snap judgments. Healthy rose canes aren't necessarily uniform in appearance across different types of roses, and some are more naturally mottled or pale or grey than the traditional Kelly green canes I like to watch for. Plenty of years I've pruned more than necessary off my hybrid musks presuming that those dark grey canes are dead like the black ones elsewhere only to discover perfectly fine interiors. It doesn't necessarily hurt them if well-established, but surviving cane is so rare for me in years like this I hate to miss any. Like anything else, it's a process of learning what is characteristic for your zone and roses.

Cynthia

Thanks, Cynthia. There are two seasons of the year, college basketball and roses, which fit together exactly at the edges. So I reappear annually when the NCAA tournament gives way to pruning time.

Rosecandy, yes I shall certainly do that, thank you...

OK Michael, you're forgiven for giving us the slip, but the real question is - did you back Duke in your bracket from the beginning or get swayed by all the press about Kentucky? A good NC fella like you needs to trust the hometown boys. When I do a bracket, I routinely put UNC or Duke at or near the top (strong family connections all over NC), and history has shown those are pretty good bets.

Cynthia