These comments are directed towards the the question: "Also, how do you clean a virused plant using cuttings? My experience of virus, admittedly not any which affect roses, has been that they are generally systemic," ------------------------- It is common to read in the general rose virus reviews something along the lines of the following: "Cuttings from an infected plant will be infected - no matter what portion of the plant they were taken from. The disease is systemic: The entire plant is infected, whether visible signs of the disease are present, or not." see as one example: http://www.goldcoastrose.org/ A Cornell 1998 rose virus research paper (not in the cited abstract: http://www.actahort.org/books/234/234_53.htm The statement is in the "must be paid for" full paper.) stated: "Virus distribution in apple, plum, and cherry trees is irregular" (they then give 1963, 1973, 1984, and 1986 references.) it is likely that virus distribution in rose is also irregular. This explanation appears to be reasonable since virus inoculated plants frquently exhibited some shoots expressing no symptons. It is possible that the virus has not been distributed throught the plant." ------------------- Since then, one French http://apsjournals.apsnet.org/doi/pdfplus/10.1094/PHYTO.2000.90.5.522 and one Polish study http://150.254.175.4/ptfit/pdf/PP38a/PP38_091-098.pdf have confired the irregular distributions. -------------------- The French reported that: "A total of 89% (59 out of 66) of Anna stems was entirely PNRSV negative when axillary shoots from these stems developed after the decapitation of the floral stem, after the development of cuttings, or grown in vitro were tested by ELISA. ELISA tests of leaves from these stems were all negative. Since IC-RT-PCR conducted in parallel on all the explants from three (out of seven) of these stems also were negative, we suspect that these stems were virus free, even if they belonged to infected plants, or that the viral titer was very low in the stems." http://apsjournals.apsnet.org/doi/pdfplus/10.1094/PHYTO.2000.90.5.522 ---------------------------- Thus, the French reported that they suspect that they were able to obtain clean plants from cuttings (as determined by the use of ELISA or PCR). They leave the door open that a more sensitive method may find a low amount of infection. ---------------------------------- This is what was reported concerning California Davis ROSE VIRUS experience: "Oddly enough, one way they eliminate virii is by clonal propagation. Simply put, if you culture enough buds (~100) some small number of them (two or three maybe) will be virus free. The drawback is space, labor and the need to index all the test plants." http://www.rosebreeders.org/forum/read.php?2,38492,38492#msg-38492 See the following thread for a discussion of the possibilities of cleaning cuttings in a hot climate. Here is a link that might be useful: garden web thread on possibilities of cleaning cuttings

Henry, your statement "Is the pruning and cutting shears warning relevant to PNRSV in roses?" Response -- found in this paper: http://pub.jki.bund.de/index.php/JKA/article/download/605/1515 Pertinent statements from above paper quoted below: "PNRSV and ApMV transmission by seed, pollen, on cutting implements and by root grafting from infected plants to healthy plants has been reported and the results showed that root grafting is involved in the natural spread of the virus in roses (Golino et al., 2005)." Note "...and the results showed that root grafting is involved in the natural spread of the virus in roses." This means that claims of transmission via "cutting implements" were dismissed because of root grafting. Root grafting would require that roses are planted very close together, and results in contact more intimate than occurs via pruning equipment. Also: "Because the only proven means of transmission of RMD in roses is through vegetative propagation of infected buds, scion or root stocks, the use of clean and virus-tested production material is essential to improve productivity in gardens." When you pull up references that say what you want to say and post them in isolation, you are neglecting to acknowledge that those statements were later further evaluated and discounted. The paper I cited is from 2010. Any rebuttal of the above must therefore be more recent to be taken seriously. :-/ ~Christopher

When several of my roses (but NOT my two Double Knock Outs) came down with RRD, I waited until the following early spring to replant in the same spots, but only because I was ordering bareroots which are sent in late March/early April. Whether that 6-9 month wait was needed, I have no idea. The several cases of RRD did NOT spread to any adjacent roses. In fact, each case happened in a different year and to a rose nearly on the opposite side of the garden. I think we still do not know enough about this disease to make very many safe generalizations about it. Kate

In my garden, Dr. Huey returned every year for 10 years despite digging a couple of times a year, as much root as I could (down about 2 feet until I hit too much rock to dig) and spraying the shoots with RoundUp. For a couple of years I was covering the area with black plastic as well. He grew from the roots outside of the plastic area which was about 4x6'. This is with no irrigation, but I think the roots went into my neighbor's irrigated garden. If I had to deal with Dr. Huey again, I would spray with RoundUp, and cover with two layers of black plastic, and spray the light starved shoots every month for a couple of years at least. I wouldn't plant another rose over that area, because Dr. Huey will just grow through it. He can also break holes into the black plastic and grow through the holes. I vowed never to plant a grafted rose again, although many of David Austin's new releases are only available grafted. I'm removing my roses that are on Dr. Huey (i.e. Grande Dame and Boscobel) and either planting them into pots or putting them into the trash.