I keep reading that there are 5 or 10, sometimes 15 or more different strains of black spot. This, I'm led to believe means that blackspot life forms are like the BORG.
So obviously resistance is futile.

But if indeed it is a hoax, then it seems that even HMF has been taken in because I increasingly find rose descriptions that include a shocking new term:
"black spot resistant."

Or maybe black spot resistance is a clever deception to fool folks, who don't, or won't, or for whatever reason cannot apply chemicals, into buying certain roses in the hope of having healthy ones.

If so, IMHO, it is a much cleverer ruse than that deceptive practice I so often observe on this forum which is posting photos of roses that ARE chemically treated while "inadvertently" neglecting to mention that fact.

Or similarly, highly touting the "disease" resistance of a rose grown in an area where black spot rarely causes a problem.

I remember one post where when questioned, the author responded that she never said anything about BLACK SPOT resistance. She had after all only said "disease" resistant.

These have been VERY long running acts, or should I call them....

Blackspot resistance must be a hoax.

Just wondering...

Jackie

After reading comments here for many years, I conclude that the areas with the heaviest blackspot pressure and/or most virulent races are the Mid-Atlantic from NY down to DC and here in Appalachia. Pressure is less in places with very hot summers and less frequent rain. One peculiarity is that in my area we have BS that can defoliate the tea and china roses that are mostly resistant in the deep South.

When I mention BS resistance for a variety, I try to remember to say "for me" or "in some gardens."

One way to find disease resistant roses is to visit nurseries and public gardens and look for roses with clean leaves surrounded by diseased plants.

Then you need to do some research to see if the plant has issues. For instance, Geoff Hamilton is highly disease resistant--but is noted to be a stingy bloomer by many folks and is frequently shovel pruned.

Once bloomers often have good disease resistance, but there are exceptions. The Fantin Latour in our yard has lots of spotted leaves. It has also won Victorian Queen, so it stays, while Geoff is available to anyone willing to dig it up...

I have to admit--I am amused occasionally when I read a poster's claim that such and such a rose is highly disease resistant--and then a sentence or two later admits that he/she uses an anti-fungus spray in their garden. Since the job of an anti-fungus spray is to eliminate the fungus, I would think a sprayed rose probably would exhibit good disease-resistance. Like, duh!

Anyone who doesn't believe some roses are more BS-receptive than other roses, please come and compare my Gypsy Carnival HT with any other rose in my garden. The difference (in terms of black spots) will be immediately observable.

That reminds me--I do need to get rid of that Gypsy Carnival--but I do love its gorgeous red and yellow blooms, despite its bare-naked canes!

Kate

By far the biggest thing I learned from the exhibitors, is that *YOU* are in charge of the asylum that is your garden. If a rose doesn't perform under your care regime, and your care regime isn't totally disconnected from reality, ditch the rose. Because there actually are a fair number that will defoliate even with a serious spray program. There are a lot that will defoliate with a spray program that follows the recommended upper limits. So it helps a lot to decide in advance how far you intend to go because sometimes doing whatever is necessary isn't enough.

Anyhow: I'm almost 100% certain I've never seen any blackspot on 'Belinda's Dream'. Like, 99.99% sure. I bought it specifically because it's considered one of the most disease resistant hybrid teas. From the same breeder, 'Basye's Purple' is almost disease free, but is such a thorny thing I come close to removing it every year.

A couple other roses I tried...from breeder/collector Paul Barden IIRC...were terribly bedeviled with black spot and various other foliar issues which would have required spraying. I still have one and got rid of the other.

Once your accept the fact that "disease resistant" does NOT mean "disease immunity," it all becomes a lot simpler--and considerably less aggravating!

Kate

Disease resistance is one thing that the buying public (me included) look into when making purchaser decisions. It is too much to ask the vendors to refrain from exploiting the label. They would be right too: there is bound to be somewhere a rose WILL do well, but just in your or my neck of woods. Exhibit #1: Golden Celebration in full Austin regalia sold for about forty dollars a pop at Northern Jersey nurseries with that Austin label proudly proclaiming that it is very healthy.

Then there are the occasional headscratchers: my Sunsprire was BS free for 4 years, and this year she won the prize of most barenaked rose. Might be a case of bs mutation overtaking Sunsprite's immune system.

I don't spray for foliage disease, and rely on my roses being healthy without chemical assistance. That said, the disease resistant label can be misleading and, as in other situations, it is buyer be ware.

I'm not accusing any of them of deliberately deceiving the public, but evidently in those cases, they have only a particular region of the country in mind (no BS pressures in parts of California does not mean the rose is BS-resistant in all regions across the country!) or, in their eagerness to sell, they have "inflated" the positive statements about disease-resistance.

I usually take it that if the rose description says absolutely nothing about disease-resistance, then the rose probably suffers from BS problems, at least in a number of regions.

And as I've mentioned before, David Austin rarely mentions disease-resistance (too negative). He usually talks about how "healthy" certain roses are (they are BS resistant) or he, like the other places, says nothing (the rose probably attracts BS). I notice that a couple other places are beginning to use the more positive designation of "healthy" in place of "disease-resistant" also--which is fine with me, as long as I can figure out what they mean.

I would still argue that, on a public forum like this, most posters mentioning "disease-resistance" mean "bs-resistant"--unless they go out of their way to specify rust and mildew resistant.

As to why a perfectly good rose, after a couple years, suddenly develops BS problems, I haven't a clue. But I also have a couple roses that started out with some BS problems, and after a couple years, seemed to "outgrow" most of those problems. The best explanation I can give for that is that they got stronger and more mature and therefore more capable of resisting BS problems. But I'm guessing on that.

Kate

Kate

Asylum. That's great!!!

I know that when I made my first mistakes with rose selections - back then I'd look at those roses and think I was running a sanatorium.

So glad I gave that up early.

I keep trying to understand your statement:

"I have to admit--I am amused occasionally when I read a poster's claim that such and such a rose is highly disease resistant--and then a sentence or two later admits that he/she uses an anti-fungus spray in their garden."

And I keep failing to understand it.

Yes, you also wrote:
"Since the job of an anti-fungus spray is to eliminate the fungus, I would think a sprayed rose probably would exhibit good disease-resistance. Like, duh!"

But my question remains, how and why is it amusing?

I think you've got it, Michael. There are many different fungal diseases that all fall under the name black spot. A rose may be resistant to one or more of them but then succumb to some others. Without a way to test which are which and which ones effect which roses and which strains are present in your garden it's impossible to say definitively that a rose is BS resistant to any of them.

It turned out, they appeared to be resistant to blackspot, where tested ... (a disease we rarely see). They were just not tested for rust or mildew.

Jeri