Kill more.

Right now, it's been so cold that I don't think any eriophyid mites are anywhere close to active. I know the Nashville area is a bit warmer than east Tennessee (my part, near Knoxville), but right now you're getting the cold from Canada several degrees worse than we are.

The canes themselves when dead aren't going to be mite attractants; there's nothing there for them to suck.

My question would be: is one application of Round-Up going to do much of anything at this time of the growing (non growing) season)?

But this is the growing season in these parts.

The county road crew came through the road at the bottom of our property last week and there is a persistant multiflora there that we've tried to kill. Several days after they opened the area up to sunlight, but removing small trees, a really ugly witches broom appeared, in vibrant magenta, in the middle of the multiflora that we had throught was RRD free.

Down here, the multiflora is just waiting for an excuse to start growing vigorously. Temps next week are supposed to approach 70's (sorry about that, northern Ohio HK) and when the soil around the multiflora roots heats up, the multiflora will grow.

My polys that are Orleans rose related (closer to multiflora than most other polys) have already put out the beginnings of leaf growth, but somewhat smaller than they should be because it's been cold down here.

Thank you very much Ann!

Henry, I'm not sure. We are warm enough for new growth and leaves to emerge so I think it is a least worth the effort. I did this last year a couple weeks later in the season with very good success. Some of the plants are so overcome and sickened with disease that I wonder if they could recover from simply from being pruned to the ground.

I'm very limited in the time frame I can do this--once some of these thickets and overgrown fence lines get much Spring growth I physically can't access the multiflora. This isn't my property so going in and doing a mass clearing of the fence lines and thickets isn't an option.

Ann, off topic...but what is the rose that grows EVERYWHERE around here and has tiny pink blooms?

Tammy

I guess this point should be brought up. Since the multiflora are downwind, why are they of concern? Are they close enough that the mites could hitch a ride on birds, bees, other possible carriers?

The multiflora are down wind of the prevailing winds, but we get enough windy, violent weather that they aren't downwind every single day--just most days. And yes, close enough that my dog runs through the thickets and then comes 30 second later romping into my gardens--this area is for all practical purposes directly adjacent to my back yard.

And the original plan--which is currently on hold--is to put climbers and ramblers on the fence line itself. It would be crazy to do that and not try to do something about the multiflora a few yards away...It is still might be crazy after getting after the multiflora.

Downwind roses aren't a problem, except when the wind shifts.

Those shifts, nasty things, happen every time a front goes through.

Some TV stations use a map that shows wind directions for the whole country. IF you have such a station that does a time lapse, watch the shifts.

If not, take a look at the isobars around a Low. Isobars are lines of equal pressure. On an isobar, in the northern hemisphere, the wind direction is totally predictable around a Low. It goes from farther from the center of the Low towards the center, but not at a vector normal to the Low, but at an angle that is about 30degrees to the line of the isobar. The winds, simplified, move from out to in and swirl towards the center. As the Low moves past, the wind directions shift.

That's why predominant wind directions matter, but the entire spectrum are a potential risk, especially when there are sick roses in proximity to our roses.

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Now about the rose with tiny pink blooms.

If they are five petaled, once blooming and killer fragrant, they are probably the natural variant on R. multiflora which is light pink.

If they are multi petaled (15 or so), once blooming and may not be fragrant, they are probably Dorothy Perkins. At the turn of the last century, a lot of wonderful healthy rambler roses were introduced, and many, many civic organizations planted these along roads to beautify the countryside. Dorothy Perkins is one of maybe ten that were planted often in Tennessee. Dorothy also survives well.

IF they are repeat blooming, then they may be seedlings. I have a (heh, heh) volunteer that fits that description that came up in th middle of my herb garden, and it IS a keeper.

Really simplifies in the first pix on this webpage

Here is a link that might be useful: Under jetstream

I would spray the multiflora thoroughly with Roundup, let dry, then spray with Wilt Pruf to immobilize any mites. After a few days for absorption and translocation you can start removing the canes and painting the stems with another dose of herbicide. Mites may be relatively inactive now, but I assume they would try to leave any rose tissue that is dying and drying out.

Thanks Ann...they do look like Dorothy Perkins. I grow Super Dorothy and its blooms are a little darker than this wild rose I think, but its the same bloom form and is once blooming. This same rose is even growing in the middle of the 10 acres we just bought. I guess it could have been a "gift from the birds" :)

Ill try to get a picture of it blooming this spring. I even have some of it that I rooted when I was experimenting with different rooting techniques.

Tammy

When does the pink multiflora bloom? And when does Dorothy Perkins bloom? I have a glorious stand of wild pink roses in the meadow that bloom in late summer. Now I'm wondering if it is the cause of RRD that plagues my gardens. I have not noticed any witches' broom, however. I have been loathe to get too close to investigate because of all the PI that guards the area.

Pink multiflora is just like white multiflora, identical bloom times.

Late summer bloom in central Illinois isn't multiflora. Wild and pink and late once blooming might be Rosa setigera, does the stand have great fall color on the leaves? Or could it be that it repeats, only the other plants overgrow it so you don't see a second or even third bloom?

If a stand of roses gets witches broom/RRD, you'll know it by the ugliness of the leaves and canes and then the blooms won't be "right", if it blooms at all.

I wonder if a thick solution of horticultural oil would be as effective as Wiltpruf and probably cheaper. Ann at one time recommended using hair spray to immobilize mites.

Two of us spent almost 3 hours yesterday cutting multiflora canes then painting them with RoundUp. We are probably only a third of the way done in getting to everything I'd like to remove.

A handful of the bushes deep in the fence line had canes 3"-4" in diameter so we had to use a hand saw instead of lopers for those. We probably cut down 40-50 bushes and maybe all but one or two were diseased. I'm afraid there wouldn't be enough WiltPruf in the state of TN to supply all I would need for this job! ;-) Nor would I want to spray (or pay for!) that much RoundUp.

The best news is that the acre or so I did last year with this method still looks free of multiflora. Even without spraying to entrap the mites I'm thinking I'm better off than just leaving it all growing.

I've got my helper coming back in a few days for another round. I'll try to get some pictures to post.

Thank you everybody!

Question: of all those sick multiflora, was there any sign that RRD was killing any of them?

Wow, Ann I didn't even think about that. I don't recalled seeing a single multiflora bush looked like it had given up and was flat out dead. We worked on several big bushes (6x6) that had a least a dozen+ canes most of which were dead, but still with a couple, three viable canes that were long, snaking, skinny, and fully infected.

When I go back I'll specifically look for dead bushes. If RRD is fatal why wouldn't there be dead bushes? Timing?

Hint:
When RRD was spread intentionally out in Iowa, it was done at the behest of the Beef Producers of the southern tier of Iowa counties who had a lot of multiflora in their grazing fields and they didn't want to kill it themselves, they were looking for a "Bioherbicide".
What I've seen in the more eastern part of this country is that RRD doesn't kill roses all that fast.
Your adjacent field sounds like some others I've seen (back when I didn't think to count living vs dead plants, because I hadn't thought the contradiction through) where the infection can build and build and build for several years and the field remains a mess for grazing, etc.

To attest to the power of painted on RU on rose stubs - I had what I think was a Dr Huey that came with the property. Very tall, only had blooms up at the tippy top, and when I chopped it down the first time to get new growth, the second growth came back identical - tall, leggy, leafy only at the top. Not beautiful, and in a bad place. Some of the old canes were well over an inch thick. The day I'd finally had enough, I chopped it again, painted undiluted RU with the paint brush and left it alone. No spraying, no wind worries, just easy peasy painting it.

I had growth within 2 weeks after the first chop. It's been 2+ months since the second chop, and there is NOTHING there... I'm a believer.