I have found that a fair number of cultivars that are free from Blackspot susceptibility are often far more likely to get Cercospora. I doubt this is a coincidence, but I am also uncertain what conclusions, if any, can be drawn.
I just can’t resist.
My most favoritist Carefree Delight seedling, todays pic (of course we’ve had a week and half of solid rain- so its been bruised).
It’s not like the CD x Multiflora seedling in the disease dept, but I’m not complaining much.
Now, I don’t get it… I tried to resize that to 320x240. I’m sorry it went wrong.
…and then it turns out right. Computers, gotta love em.
Years ago I had a spontaneous seedling of The Fairy come up in the garden. The blooms looked just like moms. I dug it up while it was still young and it died. I haven’t worked with it any but it seems like it would go good with Excellenz von Schubert.
I would never, ever work with ‘The Fairy’ because every plant of it I have ever seen had crown gall. It appears to have a genetic propensity to the condition.
Crown Gall and mildew, both probably inherited from the early Poyanthas. The Mother’s Day series did both to me as well.
‘Alba Meidiland’ and ‘Lady Carolina’ are really bad for this as well.
Sadly, R. wichurana is the primary thing they have in common.
Well, they have another thing in common: rapid green growth, which maybe increases the chance of this.
Wow, that’s really interesting Robert about the crown gall and ‘Alba Meidiland’. There is one I saw that had symptoms of it all along the nodes of some of the branches on the plant. In a plant physiology class I learned that sometimes the plasmid from the bacteria can travel up the vascular system independant of the bacteria and still genetically transform cells like it does with plant hormone genes to cause cell division and expansion. Hmmm. I really LOVE the health otherwise of ‘Alba Meidiland’ regarding black spot. It only gets a little mildew here, but fortunately mildew is less of a problem in MN.
‘Alba Meidiland’ was the worst I’ve ever seen for this.
I once pulled up a cane that had rooted along the ground. At each node there was a large gall. Several were the size of golf balls.
It went, pop pop pop pop… as I pulled it out of the ground.
Ugly!!!
The infection had to be vascular. I’ve grown roses in the same location since with no sign of the disease.
First let me say I apologize for hijacking this thread further (and not even pretty pictures this time) but I’m no expert. I’m continuously growing as a gardener which is why I enjoy yall’s expert advice.
I really had no clue what crown gall was.
That said, Paul you had me on all fours out crawling under thorny roses to dig around and inspect ‘The Fairy’ for evidence of it.
You get to see the deplorable conditions in which I grow my roses…put them in and forget about 'em.
This isn’t crown gall is it?
What I think happened is that the original bud union died leaving an own-rooted piece of fairy to grow (which is why I hate budded plants and much prefer own root, and why I try to pick budded plants with low unions to plant just barely below the surface… and which is only successful on some).
Why any propagator would bud ‘The Fairy’ is beyond me. It would make a good beginners rose to learn rooting techniques. It’s notorious for walking away from you by spreading and rooting laterals, I’ve dug numbers of them up to give away.
Must say that I have grown ‘The Fairy’ for years in different locations around New South Wales and Tasmania (Australia), and have never seen it with crown gall. I have ‘White Meidiland’ growing here on its own roots (MEIcoublan, not MEIflopan) and it seems pretty good so far (taps head)… but then I’ve never seen crown gall on anything here. My current ‘The Fairy’ parent plant is a stout very old plant with a trunk some 5-6 inches across. I moved it a few years back and in doing so cleaned the roots up and cut them back (because I also cut the top back severely) and the roots showed no sign of gall anywhere. I find ‘The Fairy’ gets quite bad blackspot here at times and I find the OP seedlings small and non-thrifty compared to other polys such as the one I have that is either ‘Raymond Privat’ or ‘Baby Faraux’ (think it’s ‘BF’ but others here think it’s ‘RP’). The seeds from this one achieve almost 100% germination and grow super fast and strong - get’s blackspot here though the seedlings so far seem clean of ailemnts common in greenhouses and are a good 10cm tall less than a month after germination. Nearly everything wichurana-based gets blackspot here.
Shane,
I don’t remember you mentioning in this thread but for some reason I’m thinking that I remember you being in Pennsylvania? Here in Maryland which should have similar disease pressures, I was just taking note of the general leafiness of several of the roses that I still have left at my parents’ house.
Best of all, with hardly a leaf marked or dropped would be:
Rosa rugosa
Close behind that in health, with only the extreme lowermost leaves missing:
‘Blush Noisette’ - I’ve had it for years and never paid it much attention, but I’m really starting to appreciate this
tough old bird.
With a few more lower leaves lost (maybe lower 1/3 of bush)
‘Carefree Sunshine’
‘Knockout’
‘Mutabilis’
Looking very pitiful - bare canes with a few leaves at the tips are the few Hybrid Teas and ‘Dr. Huey’ rootstocks that are still clinging to life.
Out at my house, I have a beautiful specimen of ‘Home Run’ that looks almost as untouched as the rugosa. It’s growing in a relatively isolated spot though, so it probably hasn’t been exposed to as much disease as these roses have (at my parents’ house).
Tom