Do you have other roses around which might be affected by RRD if it IS RRD and you don't remove the Knock Outs? Are any of the others which haven't died looking any better this year than last? If it IS RRD, you will need to not replant roses for a while after removing the infected ones. If there aren't any other roses around to be affected should it be the disease and if the remaining ones appear to be recovering, what would be the harm of leaving them to see what will happen? (other than not having it be the show stopper you planted it to be?) Kim

What zone are you in? That could make a difference on some of the advice. I would guess that most zones 6 and higher (maybe even 5 and higher) should be definitely showing new growth my now. I'm in Zone 6 and mine are bursting with new leaves and quite a few newly formed buds as well. So I'm guessing that if your roses haven't shown any new growth by now, they are deader than a doornail--though in that case, I would wonder if it wasn't caused by excessive amounts of Round-up. I don't think RRD kills off a rose in one season--but I'm no expert on RRD.

Certainly, if it is RRD, get rid of it as quickly as possible--before it gets passed on to your other roses. And by the way, excessive prickles isn't always found on RRD plants, so don't rely too much on that "symptom" by itself. The distorted witches' broom growth on the ends of canes is much more significant when it comes to detecting RRD, in my opinion.

But do feel free to take pics and post them here when you think you might have a case of RRD. Lots of "experts" will weigh in on the diagnosis--which is hard to do with NO pic.

I'd replace a couple of those KOs--Home Depot should have some. I saw some real healthy looking ones at my HD just the other day. But I'm a bit impatient to get results sometimes--which is why I wouldn't wait to replace them.

Good luck.

Kate

Another question, you describe it as a "knot garden". Are there shrubs such as myrtle or box wood used to surround the Knock Out beds? Have any of these shown any damage? If it was herbicide, and there are other plants around the affected roses, surely they would also show some herbicide damage? Posting photos of the knot garden, the roses and any other plants in the general area which may or may not have been affected by the potential chemical damage would help diagnose the issue. If there are other plants among or around the roses and they show some damage, herbicide could easily be the cause. If the other plants show no affects and should have also been hit with any over spray, RRD is more likely the cause. If there are no other nearby plants, you're still left pretty much in the dark. Kim

Thanks all. Zone 6 here - Central NJ. The roses are surrounded by boxwoods which show zero sign of any damage. Only the roses. The "new growth" that some of the KOs displayed were the bright red weird growth that I saw on them last year. It resembles the witches broom images I've seen posted to RR sites. Two of my roses were deader than dead. I will try to grab a photo. This really "bites" because I was so excited about the propect of growing a new climber over my arbor. Ugh

RU damage usually looks like stunted wispy growth. RRD is usually more growth (witches brooms, red growth and hyper-thorniness). Based on what you describe, I'd say it was RRD. I would remove any of the KOs that showed any of these symptoms and keep an eye on the rest. If the badly affected roses are 'deader than dead' the danger of mites traveling from them to new roses is probably nill. But there could have been other roses that were infected and just haven't shown signs yet. You just have to be vigilant. If you can catch this early enough you can remove one cane and save the rose.

I agree with Buford. I saw Roundup damage at my neighbor across the street: she sprayed on her dandelions and got her peonies & roses as well. The top growth got wilted & withered.

RRD is completely different. I removed an RRD rose from my garden, it's healthy growth, but red witches broom, and super-thorny, even the thorns are red. RRD is caused by a wingless mite which transmits the virus inside the tissue of the plant, and screw up the RNA replication process of cell division.

In thread after thread the same people insist that because they observed round-up damage on a certain rose that someone else's rose cannot have round-up damage because their symptoms are different. Yet article after article states that the 2 can be similar. I even prepared a web page on the subject that linked to descriptions and pictures.

This is damage that is showing up the second year so if it is roundup damage it is coming through the roots or through the buds/bark.

If I removed the captions from the Roundup pictures in the following link, would you be able to say the damage was Roundup or virus?
http://plantpathology.uark.edu/Number5-2009.pdf

Apparently central California does not have to worry about the virus (so far). This is the description of Round-Up damage that they observe. http://www.marinrose.org/fastfacts-herbicide.html

Please notice how varied the symptoms are.

Particulary, please notice they include: "Strange looking, thickened growth, often dark red or purple in color".
Also please notice: "Often seen in spring after plants have been exposed in fall or winter, during dormancy".

Here is a link that might be useful: my web page

Henry, yes, they can appear similar. But I doubt getting a drift of RU would make a rose 'deader than dead'. His roses had RRD.

I have seen both, and yes, I would say that first picture (on the left) was RU rather than RRD. Or, at the very least, I would have watched that plant to see what developed. It is stunted wispy growth, just as I said in my post. The others show overgrowth and hyper thorniness. Those are RRD. To me, the difference is very clear.

Also, his roses are already dead and will not come back. So removing them does no harm.

Thanks everyone. I sincerely appreciate your knowledge and input. My plants definitely had the witches broom appearance which makes me fear it was RRD. Plus I had attempted to prune it out last year (refusing to accept that it might have been RRD) but it came back again this Spring - except for those plants which flatlined. I have another bush that I haven't checked yet. It is on the other side of the garden. Will let you know. -Chris

The following was stated: "The others show overgrowth and hyper thorniness. Those are RRD. "

H.Kuska comment. But the top one on the right says Roundup damage.

Compare the top left picture with the top left picture on the next page. If I switched them, could you detect the switch?

The following was stated: "But I doubt getting a drift of RU would make a rose 'deader than dead'. His roses had RRD."

H.Kuska comment: Roundup is intended to kill. RRvirus is expected to take several years (see dublinbay's comment). What zone are you in? If it is a cold zone it is possible that the 2 roses could of died from freeze damage due to being weakened by either RRvirus or being weakened by Roundup (plus both could have stimulated growth into the winter).

Of course there is no question about removing the dead ones.

"For example, distortion and witches broom symptoms may be suggestive of chemical injury from glyphosate (e.g. Round-up) or growth regulator (e.g. 2,4-D) herbicides."

http://www.ca.uky.edu/agcollege/plantpathology/ext_files/PPFShtml/PPFS-OR-W-16.pdf

Here is a link that might be useful: Plant Pathology Fact Sheet

Having never had "the pleasure" of having to deal with RRD, thank the Lord!, I would have to base my suggestions upon the absence of spray damage on the box woods. Round Up is non selective. Whatever it drifts on to, unless they are very waxy and the stuff just drips off, gets damaged or killed. I know box wood can be damaged by it as that I have witnessed. The only weird growth I've encountered here was on two body bag roses i bought from Home Depot twenty-plus years ago which broke into the witches broom type growth right off the bat. I didn't know what it was and didn't want it to get loose in the old, huge garden, so they were dumped, cans, soil, plants and all. Kim

Yes Henry, I could tell the difference and I have in my own yard.

The End.

There definitely is RRD in central NJ. I would not delay in removing the affected plants.

Regarding boxwood as a "canary". I have seen statements such as roses are particularly susceptible to Round-Up. I have also read that some plants are particularly resistant. So I decided to look to see what I could find about boxwood. The link below is to the label. For some unknown reason I could not cut and paste. Use your PDF find command to search for what it says about boxwood.

http://www.pbigordon.com/pdfs/ProntoBigNTuf-SL.pdf

Here is a link that might be useful: label

Roundup has been around for almost 40 years and I have been growing roses for about that long. I have looked at a lot of roses, and I never saw the fat, thorny overgrowth until RRD came along about 10 years ago. So I think it is wise to assume that fat, thorny overgrowth is RRD. I have paid a high price for being too slow to remove the first case of RRD in my own garden.

If you see tufty, ribbonlike foliage with exaggerated stipules, it is Roundup damage. Some other symptoms might be Roundup damage or RRD. But it's wise to err on the side of caution.

The following was stated: "Roundup has been around for almost 40 years and I have been growing roses for about that long. I have looked at a lot of roses, and I never saw the fat, thorny overgrowth until RRD came along about 10 years ago. "

H.Kuska comment. Can you post some pictures of what you feel is definitive RRD?

Also when did Weed and Feed type lawn products become popular in your area?

Henry, regarding weed-and-feed, no broad-leaf herbicide has ever been used in my yard or garden, and the nearest lawn where weed-and-feed might have been used is across the street in a small back yard. Generally in my steep neighborhood. people don't have typical lawns.

My other fairly extensive experience with probable RRD is in two public gardens. One uses no herbicide, as they told us when the first RRD symptoms appeared. The other has used Roundup in the mulched rose beds. In the latter, they do not fuss over the turf at all and probably don't even fertilize, so I doubt any broad-leaf herbicide has been applied. Obvious Roundup symptoms of the narrow, curly type appear from time to time.

Michaelg, my weed and feed question was a follow up to your 40 years of Round-Up use statement. I cannot remember when a significant number of gardeners started using Round-Up nor when a significant number of homeowners started using Weed and Feed type products. I was hopeing that since you knew about Round-Up use you also knew about Weed and Feed use (time wise).

It seems that most people have at most a few cases a year.
Why did you lose so many roses? Have you ever posted an in detail explanation of what you observed, when, and what steps you took, when? I know that you stated that you used Round-Up once on the roses. Did you use Round-up on anything else? Did you observe or ask the neighbors, whether they were using Round-Up? Did you use a magnifying glass and observe the mites? Also, how did you rule things such as a herbicide contaminated mulch batch. The last may sound far fetched but I have posted news articles about it happening and I did have bad mulch happen to me one season (I had posted it here when it happened. I immediately removed the mulch and watered heavily.)

Back to your statement: "So I think it is wise to assume that fat, thorny overgrowth is RRD."

H.Kuska comment. I still would like to see pictures of what you mean. Earlier I posed that Round-Up could result in "Particulary, please notice they include: "Strange looking, thickened growth, often dark red or purple in color"."

It would appear that "thorny" is the only property that could not be caused by Round-Up in your model.

On my web page I state the following: "I am hesitant to include the "excessive growth of thorns" rule as it may only apply to exclude damage from certain types of herbicides and not others with different modes of action. Also. often healthy young growth can have closely spaced needle like thorns which are not present in older canes. The opposite (no thorns, no RRD) is also NOT a dependable diagnostic that the cause is not RRV. Ann Peck (see E-book link at the bottom of this article) points out: "Hyper thorniness is not a dependable indication of RRD, it does alert rosarians to be vigilant. It appears on some HTs, but sick OGRs and roses related to 'R. multiflora' may have thorns no denser than ususal. Further confusing diagnoses, many classes of old garden roses are extremely thorny and no one could look at a sick rugosa, damask, or spinossissima and declare it�s hyper thorniness to be aberrant. Likewise basal breaks on some healthy HTs appear thornier closer to the bud union, but become less thorny with increasing healthy growth. This year, I have also seen a characteristic of some roses from cold hardy breeding programs to have denser thorns near the base; these roses have a built in rodent deterrent that I had not noticed until a question from New Brunswick about the possibility of RRD in that part of Canada.""

Henry,

I suppose one reason I lost (am still losing) so many roses is that my small garden was overplanted with mature roses, such that each was touching others, if not entangled. I lost four adjacent plants which included the original case, then it skipped one and got the next two. Also there are many wild multiflora in my neighborhood and even on my own very steep wooded lot (which I can hardly get around on nowadays). I did find some infected multifloras at the bottom of my lot and got rid of them. I was lucky to go so long without finding RRD in my garden. It made me a bit complacent about dealing with the first case.

I found a probable RRD shoot high on a cane of Tess, fairly late in the season, and removed the cane. I think it was early in the following season that I found a bad shoot on another cane and removed it. **I was not careful to bag the remains in either case.** Later I found a cane that was growing horizontally in the back of the plant and had produced a half-dozen nasty, fat, thorny lateral shoots, the green leaves having red veins. I removed the plant. By this time the plant had been infected for maybe 10 months. I then began finding symptoms on other plants, first in the immediate vicinity and then in other beds, usually in clusters of two or three adjacent plants.

Most (nearly all) of the plants for which I merely removed the underlying cane have relapsed and had to be removed. I have one apparent cure where I cut the whole plant down to grade. This spring, I have tried splitting the crown of a couple of roses and removing the cane-associated roots. It is too soon to tell whether that will work.