Is anyone worrying about RRD? Over the years I’ve lost maybe a dozen roses to it, one at a time. It is pretty common on multiflora in this area (eastern KS), as it is back east in PA where I grew up. Now I see it on Baby Masquerade. This is the first I’ve seen it in a mini. With all the broad experience of such a diverse group I wondered who might have seen what. And what have you done about it?
I breed a lot with New Dawn and my mother just lost its parent, Dr. van Fleet - to the disease. What are my odds?
Believe it or not it’s curable. I’ve had it in our gardens and it’s gone in all but three of the effected roses. Use a systemic fertilizer. Us it heavily toward the center of the effected plant and spread some a good 4 ft around it. The systemic will make the whole plant poisonous,roots and all, thus killing the virus. You should start seeing healthy new growth in a week or two.
It’s best to do this as soon as you see effected new growth.
To answer the first question:
New Dawn seems often to be the first rose in anyone’s garden to come down with RRD: part of this doubtless is due to the popularity of New Dawn because it’s on so many top ten lists, part is due to quality of the New Dawn (and Dr. W Van Fleet) plants out there-they don’t die in winter so more are survivors, and the third reason is that New Dawn forms a three dimensional, big rose that acts as a baffle that is a wind trap for the mites. The mites are wingless, they are carried by gusts of wind, and they drop when the wind levels drop.
Will your New Dawn get RRD? It depends on the aerodynamics of your garden as well as the density of infected mites coming in from up wind.
Last year I lost one roses to RRD; the previous year I lost 2% of my garden (over 12 roses), but I think the difference was in rainfall and the summer and fall of 2004 were wet and the mites chose not to leave their host plants.
I’ve been dealing with RRD for over five years, and my E-book (with bibliography) may help you; it’s linked below.
About the ability to cure RRD mentioned by putrid. Many folks have thought that they could cure plants by cutting off affected canes, but the disease has come back in controlled situations as late as two years later. What bothers me about making soil toxic as a test is how to you then clean the soil of a nutrient that has little mobility? In this part of the country, some (ok, quite a few) exhibitors have their soil changed out every eight years or so because the K and P levels are so high that the plant growth is affected- yet they still get RRD in their roses.
The natural test sites (that deserved to be watched) are in central Florida and in eastern NC where there are massive phosphate deposits AND wild roses. Will those two areas prove a barrier to the spread of RRD and will the wild roses there be resistant to RRD or will they just be asymptomatic.
The asymptomatic potential is the one that worries me about putrid’s garden (as well as the three un-cured roses). Other folks have seen supression of RRD-like symptoms with P additives. (Some of the RRD symptoms are caused by other diseases, as well.) Tolerance of RRD within a garden inevitably leads to infection of the nearby and down wind roses.
Because the virus lives in the roots of the plant you have to start there. The systemics are taken up through the roots and effect the entire plant. I’ve had some great success with this. Large healthy shrubs with lots of new healthy growth. On the three badly virused roses I’ve left the effected growth in place. On each of these roses I have new unaffected healthy growth. On the roses that I’ve caught early there has been no reoccurrence of the disease. for example I have a Mme Plantier that takes up a good 7 x 8 space in the garden. I noticed new growth on one cane effected with RRD. Applied the systemics and left the effected growth stay. All new growth on that cane that’s happened after the effected growth is healthy. That was a year ago. There has been no sign of RRD on Mme Plantier this year. Nor on the surrounding roses that I treated with the systemics. All the roses on either side of the three effected plants are virus free. I’ve also treated a rugosa in someone ellses garden this way. All of it’s new growth was effected. It’s been two years and the rugosa is still healthy. The Therese Bugnet has continued to grow and sent suckers two to three feet out with no signs of the virus. These folks had alread lost four huge roses to this disease before I treated the Bugnet. I tried to save an Alba Maxima of there’s but it had already been sevearly weekened having all it’s canes effected. After two years of treating it with systemics the Alba only produced two new very small shoots without any sign of RRD. They decided to dig up the plant.
If the entire plant is poisonous than it’s my assumption that the mites that cause the virus die off. It’s my guess that this would explain why none of the surrounding roses in our gardens show signs of the virus.
I’m no scientist or expert so I have no way to back up or explain what’s happened in our gardens. Or anyone ellses gardens I’ve done this to.
Ann and putrid, [addressing someone as putrid makes me laugh]
My only Rosa soulieana plant is dying from RRD as we speak. And at the risk of having an asymptomatic carrier around; I’d like to keep this plant alive, at least long enough to obtain seeds from it.
Ann writes… “Other folks have seen supression of RRD-like symptoms with P additives”
and putrid mentions that using a “systemic will make the whole plant poisonous”. Could either of you, give a little more specifics about what products are being used and how.
Thanks in advance, Tom
The suppression that I was told about was on citrus.
Re your soulieana, are all the canes involved? Or just several? And I am basing comments below on the assumption that it’s own root.
We have kept a cultivar going by taking cuttings from the most healthy cane, and five years later, there’s no RRD on the now massive clones.
It was a very old (70 year+) plant of what some say is the real Seven Sisters and there was no way to dig it up and RRD was into the roots- to the extent that it reappeared for over a year in feeder roots stretching up to 20 feet out in the yard.
But if you’ve got RRD on only part of the plant, may I suggest digging it up, bare rooting it (Hit the roots with water), use a wood chisel to split the root part that supports the healthy canes from the roots supporting the RRD canes. A friend has saved some massive climbers with a chain saw to separate the healthy side of the bush from the sick side and then keeping the bush toxic to mites with application of the systemic acaricide Cygon 2E.
LOL Tom, sorry about the name. I’m used to posting on a Halloween forum and that’s the first thing I type. How many times in life does someone get the chance to say,
“Hello, I’m Putrid”
with a strait face?
I have a thread started on the Antiques roses forum everyone with RRD should check out. I’m hoping to get a response back form Dr. Rose Gergerich soon as well. When I do I’ll post it.
So far the two things that have been tried that seem to stop the virus from effecting any new area or growth on the roses are Wilt Pruf and using a fertilizer with a systemic insecticide.
“So far the two things that have been tried that seem to stop the virus from effecting any new area or growth on the roses are Wilt Pruf”
That’s not at all what Kaye has found. Kaye had a single case of RRD on a newly bought rose four or five years ago. Whether it came in with the rose, bought from a middleman, or whether it came in as a sping infection to her garden is unknown. She uses Wiltpruf as a spray for black spot prevention. She has not had RRD in her garden since the single plant. She grows roses on a hill top in western Arkansas in a garden with lots of trees. Wiltpruf might be protecting her roses from infection, or airflow in her garden might be dropping the mites on places other than her roses, or her roses may be dry and the mites may not find access to meristems, or her disease pressures may be low because most of her winds come from Oklahoma which doesn’t have a lot of RRD infected multiflora.
Until folks with high disease pressure (as in parts of Maryland) report no new RRD infections associated with Wiltpruf application, then we are JUST SPECULATING that wiltpruf may provide some protection.
When RRD-infected plants are left in gardens, very, very often the disease spreads. Beneficial predaceous insects may control the eriophyid mites that spread the disease, but from my garden, then aren’t a 100% protection. Nor are systemic acaricides like Cygon 2E.
Heavily sprayed rose gardens that have systemic insecticides as part of their schedules still loose roses to RRD throughout the eastern USA. Ask the rose exhibitors of northern Ohio, and stand back and be prepared for tales of Woe.