Josh, it is wonderfully behaved in my garden. ARE makes claims of good health and strong growth for MB/Jacques Cartier. Liz Druitt thinks it's a winner (The Organic Rose Garden) and William Welch in Antique Roses for the South states that MB/JC "...is among the easiest and most rewarding of the old roses to grow..." but warns that it "...does not like alkaline soils." Great recommendations from some knowledgeable sources in your area! My suggestion: give it a bit of shade (afternoon) so that the flowers last longer and remain deeper in color. Carol

It's a perpetual question, debated with much heat once upon a time, as to whether 'Marquise Boccella' and 'Jacques Cartier' are the same rose (pro tip: they're not). I once had an own-root 'Marquise Boccella', sold as such, and I think correctly, which, in my alkaline soil, was clearly unhappy, which is consonant with what Welch writes. I have had a budded 'Jacques Cartier' for about three decades, and an own-root one for about half that time, and, in my alkaline soil, both bloom constantly and annually zoom up to six feet in height and more (the own-root is more vigorous than the budded one ever was). So perhaps this (reaction to soil alkalinity) is another way to tell the difference between 'Marquise Boccella' and 'Jacques Cartier'! But to answer the question: For me, both have shown innocuous touches of mildew here and there.

This post was edited by odinthor on Mon, Feb 17, 14 at 17:54

Odinthor, now that is something worth exploring! I don't think anyone I've read re MB/JC has ever suggested the two labled roses may vary from each other given differences in acidity/alkalinity, but your data does indeed seem to match W Welch's experience. Maybe I'll do a little experimenting in my slightly acid clay and more alkaline amended soil. Which sources supplied your two roses, if I might ask? It would be amazing to solve the mystery of the names of the roses in commerce. I wonder what the heck I've grown in several gardens over the years. Josh, you DO initiate the most interesting threads. Carol

My original (budded) 'Jacques Cartier' came from Roses of Yesterday and Today. My own-root 'Jacques Cartier' and 'Marquise Boccella' came from Alice Flores, who for a time had a rose-selling business, grew JC and MB in rows, and noted from observing the rows of specimens that indeed one variety was consistently different from the other. My budded JC from RoYaT is clearly the same rose as my own-root JC from AF. I don't know Alice Flores' source(s).

I should perhaps add that I grew these three (both JCs and the MB) adjacent to each other, so differences in environment were as close to non-existent as could be out in the open ground.

I of course prefer JC because it is happy, indeed exuberant, in my garden; the soil question explains what formerly I found inexplicable, that there are those who like MB, which for me was as stingy and miserable a rose as ever I've had. Just as there is "a rose for every garden," there are certain roses which are not for certain gardens!

This post was edited by odinthor on Mon, Feb 17, 14 at 19:37

Thank you for all the info, Odinthor. Josh, if you purchase a plant, I wonder which one you'll receive. Carol

I don't doubt the observed differences in plants, but I have to wonder how and why they are occurring. While undoubtedly JC and MB originally were two different varieties, as far as I can tell, all of the commercial sources of MB in the United States got their original propagating material from us, and we received it from RYT as JB in 1983, heat-treated it for mosaic virus, and "corrected" the name to MB, then distributed it far and wide. One can still certainly argue which name is historically correct for that plant, but I believe the vast majority (perhaps all) of plants being sold in this country as JC and MB, therefore, must be identical, except for the presence or absence of mosaic disease? If any of you are aware of separate importations of MB, I'd be interested in knowing. I suspect there have been multiple importations from Europe of "Jacques Cartier," but Odinthor's JC came from RYT, and so must be genetically the same as most MB being marketed by US nurseries. If there is a difference in those plants, I have to wonder if one of them may have sported. But while we were growing the original infected "JC" from RYT along with our heat-treated "MB," as I recall they were virtually identical, except that the heated plants never again showed leaf symptoms of mosaic. So there is a mystery there. What is the source of the observed differences?

I do currently have a JC that is infected with mosaic. I presume it came from RYT, although I have not proven that (such proof is rather easy, since their mosaic is consistently the same, rather mild strain of prunus necrotic ringspot virus). I grow it budded to 'Fortuniana'. It is a rather healthy grower, but I'd say it's a bit more susceptible to iron chlorosis, even on Fort roots, than are our other roses.

This rose (these roses) is called 'Jacques Cartier' in Europe and is an excellent strong grower. It sounds like we have odinthor's JC. I have in on its own roots in compact clay (so what else is new) and it does quite well, vigorous, floriferous, utterly desirable. I'm inclined to think our clay is close to a neutral ph, as chlorosis isn't a big problem; our difficulties seem to have more to do with soil texture. It doesn't mind clay at any rate.
Melissa

My two year old MB bush blackspots significantly here, but blooms through it all. Morning sun, late afternoon shade, slightly acidic soil. It's one I'm hoping will develop better disease resistance with a little maturity or it will have to go.

Malcom,

The Jacques Cartier we planted in the public park is from Pickering (therefore likely a different source than ROYAT), planted in the early 1980s in heavy clay soil which is near neutral. The water, however, is high in limestone and therefore highly alkaline. It was a good bloomer and a reasonably healthy plant. I have not seen it the last 5 years or so but can this year when it blooms if you need questions answered.

Cath

Yes, Pickering would likely have a different original source. I suspect there have been numerous independent importations of JC. But I'm not aware of an importation to this country of a rose named Marchesa (or Marquis) Boccella. Most, if not all, of those roses being sold in this country should have originated as a renaming of RYT's old Jacques Cartier, but heat-treated for virus removal.

Well, the hateful JC REFUSES TO DIE in my garden despite neglect bordering on the cruel, shade, unbridled lopping, intense competion (including a rampant gladioli bed), the bloody thing is unbowed, unrepentant and in fine (hideous) fettle. My neighbour has a monstrous 12 feet high and wide specimen - after 30 years of almost total neglect, hers also seems to flourish.
I loathe the flower form (a million tiny squashed petals on a flattened bloom), dislike the fragrance,(sickly) hate the proliferation and limp growth.....but a horrible fascination bordering on the sadistic stays my hand, year on year - I can only shake my head at the tenacity of this rose's survival.

So yeah, I would suggest it has a certain innate health and vigour.

I have a Marchesa Boccella own root from Rose-Equus and it is very healthy and very floriferous here.

Malcolm,

Wish I could have been more helpful.

Cath