Oath, My brother grows roses near Chicago and when I copied your posting to him, he sent this reply:
I have a one acre lot situated more or less on the edge of the Chicago suburbs (further out is mostly farmland and further in are densely populated suburban areas). When I moved here about 20 years ago, there was no rosette virus present. The lot had several multiflora, carolina, blanda, and setigera plants growing wild on the edges of the wooded areas that separate my lot from those of my neighbors. In the first 5 years, I planted over 200 rose plants, mostly old fashioned and species roses, but also, hybrid teas and other modern roses. Soon after that (about 15 years ago), I first noticed the rosette virus on my planted roses and on many of the wild multiflora roses on my lot. At that time, I determined that approximately 1/3 of the multiflora roses growing on the 10 acre horse pasture bordering our lot had the disease and the infection in multiflora plants could be tracked from the horse pasture through the unmowed areas in the ditches along the highway out into the farmland for as as far out in the country as I cared to drive that day. I identified the disease as rosette virus (to my own satisfaction) from the description you gave me when I asked you about it. I then bagged up branches from several infected plants and took them to the Morton Arboretum where a botanist identified the disease and gave me some literature on the subject. In my experience, the disease seems to be spread through multiflora plants growing along the ditches, vacant lots, and unmowed areas. This method of spreading doesn't seem to allow the disease to travel very far into populated areas within the Chicago suburbs. For example, in the past 15 years I have not seen it spread into the Morton Arboretum's species rose garden where several highly susceptible roses live pretty much unattended. The Arboretum, and many other rose gardens that I watch, are apparently well protected by surrounding populated areas where a wild multiflora plant wouldn't go unnoticed and wouldn't be tolerated.
I think it is kind of surprising which roses are affected by the disease. For example, r. mutiflora and r. setigera are both members of the same family of roses (synstylae). Yet, I have watched, over a several year period, a large multiflora plant trying its best to smother a smaller r. setigera plant. Happily, the multiflora eventually died away due to the disease, leaving the setigera (the " Illinois Rose") healthy and growing. After about 15 years of the disease on my lot, nearly all of the established multiflora plants are dead. However, I still have plenty of multiflora seeds germinating around the lot each year. Unlike r. setigera, another synstylae rose, r. wichuriana, that I had long enough to become established, I suspect died from the disease.
Several wild r. carolina plants on my lot are at least 20 years old and have never seemed to have been ill with the disease. I think, if memory serves me, r. californica belongs to the carolina family of roses, and I have an r. californica that is also quite old and unaffected by the disease.
Members of the cinnamomea family that I have, including the species r. blanda, r. pendulina, r. arkansana, and several hybrids of r. rugosa all seem immune. I have a very old hedge of the rugosa hybrid, Frau Dagmar Hartrop, with Frau Dagmar doing OK, but whose rootstock, which I think is comprised of r. canina and r. eglanteria or some similar appearing rose whose leaves smell like green apples, throws up suckers that are almost always infected with the disease. Until recently, I had the r. blanda hybrid, "Therese Bugnet," which lived through all this but got buried and died from smothering in a spreading cluster of " R. Mundi." I had an r. palustris bush at one time, but I can't remember what happened to it.
R. rubrifolia is extremely susceptible to the disease. I had quite a few established r. rubrifolia plants that died from the disease. I also grew the rugosa /rubrifolia hybrid "Carmenetta" that I think also died from the disease.
In the pimpinifolia family of roses, I still have a large r. hugonis that is almost 20 years old and lived through all of this. For a long time, I had a r. primula that seemed unaffected by the disease but, I think it died from underground grubs. I still have a spinosisima hybrid, "Stanwell Perpetual," that is probably 15 or 20 years old and has never had the disease. I had several plants of the spinosissima hybrid, "Harrison's Yellow," or "Yellow Rose of Texas," that died over the last 20 years but I'm pretty sure from grubs and not the disease. My r. hugonis would have died from grubs had I not begun spraying the ground around it with diazinon (and after diazinon was banned, with Grubex). The dieback on the other spinosisima types just mentioned was similar to what was happening with my r. hugonis and I really doubt that they died from the virus.
I had two large old single-flowered r. roxburghii plants (the double form is called the "Burr Rose") that were unaffected by the disease. One is still alive but the other died recently from too much shade from trees planted near it after about 20 years.
The gallica roses," Rosa Mundi," " Rosa Gallica Officinalis," and "Tuscany Superb" all appear to me to be immune and survived for many years near infected plants in my yard.
The super tough alba rose, "Great Maiden's Blush" was one of the first plants to die from the rosette virus in my garden. I had a large bush that produced possibly a bushel of rose flowers at one blooming period and then died the first year that I noticed the virus in my garden. My very large r.eglanteria plant also died early in the spread of the disease.
I also grew some modern hybrid tea and grandiflora roses. These were, in the main, commonly grown modern roses, like "Mr. Lincoln" and "Queen Elisabeth." They died soon after the disease came to my yard, but, unlike most of the roses I was growing, they are not extremely long lived in the Chicago area, anyway. But I do think most of them died from the disease and I certainly didn't see any that I would say seemed to be immune. My neighbor had a very large red climbing rose, I think "Don Juan" growing on the west side of his garage that bloomed well every year until it died the same year that I noticed the disease in my yard.
If I were going to breed brand new roses immune to the disease, I think I'd be looking into the carolina family of roses which are kind of pretty anyway, and then add some r. setigera blood for climbers and nice leaves. Maybe I'd combine this with r. gallica officinalis and r. mundi roses for larger flowers with good color and scent, but then I'd also be adding mildew and blackspot. Maybe the pimpinifolia family would be good. R. hugonis is pretty nice, but I really liked a plant of r. spinosisima altaica that I owned at another location. However, I don't know for sure whether altaica is immune to the virus since my plant was never exposed. Altaica can be trained into a nice large rounded shrub with large perfectly white flowers. My guess is that altaica is immune to just about everything including cold weather-but so are setigera and carolina. I think one could produce salable plants for the landscape that could replace red twigged dogwoods or viburnams and a lot of other landscape plants. I wouldn't necessarily even advertise my new hybrids as roses, because people would assume a rose to be disease prone, tender, and certainly not carefree.
However, were it not for this particular disease, I'd still be growing roses in substantial numbers instead of the few thousand Koi that I grow in my yard today!
Q