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Can We Discuss Powdery Mildew?

carolfm
16 years ago

I normally have a few Tea's that show a touch of PM in the early spring but it isn't horrible and it resolves as soon as the temperatures warm up. This year nearly every rose, of every type, in my garden has suffered from PM in a big way. 8 foot tall roses with PM deformed leaves from top to bottom is an ugly sight. If I dug up every rose that had PM, there wouldn't be much left here. We removed a lot of roses over the past year to improve air circulation so I don't think that is the problem. Supposedly Banner Max prevents PM but I can attest that this isn't true here.

I'm not sure what is going on. Is this because of the drought? My roses are well watered and I have the water bill to prove it....Did the late freeze that damaged my roses weaken them to the point that they are showing PM along with the BS and every other disease they normally have? It's certainly been hot enough here to inhibit PM. Is this going to be an ongoing problem in my garden henceforth?

I read somewhere that hosing the leaves off a few times a week helped with PM and I tried it and I really do think it is helping some but I still have some new foliage showing signs of PM and it is hotter than hades and twice as humid.

Any ideas? Solutions?

Carol

Comments (47)

  • bluesibe
    16 years ago

    Carol, We live with PM throughout the season. Here, it is generally caused by warm, sunny days and cool nights (read that fog). I don't particularily stress about PM. If I water early enough, I wash off the leaves, if I have time I spray with Cornell spray. If the leaves are really bad, I strip them.

    Luanne has the time to deal with PM more than I do. She has a number of organic methods including diligent spraying with Cornell. Perhaps she will give you her formula.

    From the land of PM and Rust,

    Carol

  • jbfoodie
    16 years ago

    I have those warm days and cool nights as Carol does, though the nights aren't usually foggy here. I get some PM on some of my roses and do not spray. So, what I do is spray the leaves of the worst offenders in the morning with water (i.e. hose)and this seems to keep the PM at bay. I do water with a sprinkler-bubbler system--many of the my roses are in the middle of my dad's lawn, which had an existing sprinkler system at the time of planting--which seems to help as well. Most of the watering takes place at 5am, so as to reduce the evaporation inherent in such systems. However, having said all of the above, I live in Northern California and my climate is much different than yours. The days are dry and the leaves are usually able to dry off before nightfall. In your climate, you may have to spray with something to control the PM.

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  • anntn6b
    16 years ago

    Carol,
    I've got a simlar PM problem on roses that have never had it before. On the hillside, lots of windflow, as many hours of sunlight as any rose can get here...PM on ramblers.
    But the wierdest thing is that sibling plants of the PM infected plants, in the back yard, limited hours of sunlight, less air flow, cooler temperatures in the heat of the day, Tausendschoen and American Pillar are totally clean, yet their sib plants (maybe a half a football field away) are screaming ugly with PM.
    Many years, phlox in these parts has horrific PM; this year many weeds have had PM to the point of near death.
    I wonder how phlox growers are finding their plants?

  • carolfm
    Original Author
    16 years ago

    I have Phlox and there is not one iota of PM on it. It's growing in between/in front of roses that are covered with it. I am at a loss. I am trying to figure out what is happening here and none of it makes any sense. The weather is not conducive to PM. Our nights are not cool. Neither are the days for that matter. It has improved on some roses with the increased temps but I shouldn't be seeing it at all now on the new growth and I am.

    I think the Cornell spray has oil in it and I am pretty sure that oil and 90 degree, sunny days don't mix well. I will continue the washing of leaves since that does seem to help a bit.

    Ann, do you have any theories on why this is happening? I am to the point that if I have to deal with one more disease issue or pest in this garden, I may rent that bulldozer after all.

    Carol

  • rosefolly
    16 years ago

    I'm at the opposite end of the spectrum here. Over the years I have removed most of my teas because the PM is so bad most years.

    This year, however, I'm just starting to see a little PM here and there, A couple of days ago I did my first spray of the year with Remedy, a Cornell formula-like product from Bonide based on potassium bicarbonate. In fact, while I bemoan the drought, this is the healthiest my garden has ever been.

    I still wish it would rain this winter. We only had about ten inches last year. I'd love to have twice that.

    Rosefolly

  • anntn6b
    16 years ago

    And I forgot to do a rose pm search at the library the other day; I got into crown gall and some virus papers.
    I've still got some big (and now b*tt ugly) ramblers along the fenceline that seem unable to shake the PM. Some are putting out new leaves that aren't covered with white; but several look terrible. And they didn't waste their energy blooming this spring, so we can't attribute weakness to over bloom production.
    The back yard ones are good (don't ask about the HTs back there); but why should a open field fence line get sick?
    In the fungal line, some of the apples (Golden Delicious) that get some rust each year, have the worst apple rust ever.
    If it were the drought, wouldn't we see the smaller plants with less root mass and less exposure less able to kick it off?
    More thoughts later, maybe.

  • madame_hardy
    16 years ago

    My usual horrible PM has yet to raise its ugly head this year, and I usually spray successfully with GardenSafe (a neem based spray) that knocks it back. This year I'm using something called Organicide, sprayed with it from early this spring, and I only just saw my first touch of pm on one leaf the other day. Usually I'm spraying what seems like constantly for pm, and I just *manage* it; this year has been much less frequent (and much more enjoyable).

    Not sure if it's our higher temps this year, or the different spray, but whatever it is, it's been a delightful reprieve for a change!

  • robiniaquest
    16 years ago

    Ann and Carol -

    In past years I have had terrible problems with PM on my phlox and monarda, while my roses (except for a little on the gallicas) have stayed clean. This year my phlox are clean, monarda a little better than usual, but my roses are just eaten up with it. It has affected the gallicas and mosses the worst, but HPs and Bourbons have a touch of it as well. Ombree Parfaite, Rush Gallica, and Fara Shimbo have been totally covered in it since mid-spring. It's so bad that I'm considering getting rid of those roses, but I hate to because I do love all three. I've had considerable problems with Ombree Parfaite in the past, so I don't know if it's worth it. Can anyone else speak to the PM problem with regard to these particular roses?

    As for weather, I will say it has been an unusually cool and wet early summer here. Perhaps the phlox are just stronger than usual because they prefer those spring/early summer conditions, and have been able to resist the PM because of healthier vegetative growth. Just an idea. It's funny, because I was on the verge last year of eliminating them, as I've always thought of them as junky, weedy eyesores. This year they have redeemed themselves with incredible, lush, ice-cream sundae-like bloom heads.

  • berndoodle
    16 years ago

    Apparently there are many factors, included when exposure to PM occurred relative to the age of new leaves. Exposure the first three days of opening makes the rose the most susceptible. Older leaves are better able to fight off infections, which may explain why our Teas and Chinas can have better resistance - - they tend to hold onto their leaves longer, being more evergreen.

    It has been my observation that water-stressed plants are less able to garner their resources to fight off the fungus. Too much water and too little water can both generate PM if the atmospheric conditions are conducive to PM.

    The fungus spreads by sinking it's stinking little tenacles into the leaf surface. In a resistant rose, the rose kills off just that cell and a few around it, but in a rose unable to fight the fungus or maybe if the particular strain is really nasty, the fungus can spread quickly to the whole upper leaf surface. Then you've got grief.

  • carolfm
    Original Author
    16 years ago

    Therein lies the problem. The atmospheric conditions, according to everything I have read, shouldn't be conducive to PM. Yet it persists. Not as bad, but still showing up. It also seems by the comments from other people that the PM seems to be worse in most gardens in the southeast this year. That is somewhat reassuring since it indicates that maybe it isn't something I have done or failed to do.

    Cass, nearly every leaf on nearly every bush in my garden is deformed from PM. This is not normal here. I'm sure you are aware that we have had garden challenges this year since the freeze. We have monitored the amount of water the roses receive very carefully since we were dealing with already stressed plants. If this strain is indeed a particularly nasty one that has just shown up this year, will it hang around forever more? I guess I am wondering if it can be eradicated without nuclear warfare or if it will be present in my garden next year. I probably should know whether PM spores overwinter/hang around like BS but I don't or I have forgotten.

    Robin, I hope someone can help you with those particular roses. I wish I could grow them here, but I can't. I don't think I would dig up any rose unless the problem was a consistent one from year to year. I'm hoping this is an aberration of some kind.

    Imagine that the California folks don't have much PM and we are dealing with overwhelming amounts of it! The least you guys could do is share some of this BS :-) Kind of scary to think about all the weather changes, eh??

    Carol

  • berndoodle
    16 years ago

    Carol, I wish you were right, but PM is everywhere in California and no doubt world wide, ever since it was described around 300 B.C. by a Greek. Here's some info from the Encyclopedia of Rose Science (I'll condense):

    PM is a parasite that lives on the surface, not inside the plant tissue. Those pesky taxonomists have been at work again. It used by called Sphaerotheca pannosa var. rosae but to keep us on our toes they now call is Podosphaera pannosa. They dropped the "rosae" part because it's the same stuff found on peach and apricot.

    PM shouldn't reproduce at temperatures above 86 F/30C. It survives freezing temps indefinitely, 26 F/-3C easily for three months.

    While there are optimal conditions for PM reproduction (high humidity, 71 F/22C), less than optimal conditions like humidity of only 50% just cuts the rate of germination. Optimal conditions are warm, humid days without rain and cool humid nights.

    PM infects dormant buds in the fall and overwinters in them. When the buds (we're talking canes) grow in the spring, the fungus is already present. In dry weather, PM can be blown by the wind. PM can reproduce in 4 to 10 days. Large water droplets knock PM spores both out of the air and off the leaves, reducing infection.

    PM evolves rapidly and easily develops resistance to fungicide. This is simple math: spores are clones by the millions, so a single resistant clone wouldn't be all that odd. Rotating sprays is very important, such as using both a strobilurans (like Compass) and rotating in an old fashioned, broad mode action fungicide like sulfur, superfine oil, bicarbonate salts or plant extracts. One two punch.

    So there you have it. The way I see it, if there's air to breathe, PM will grow in it.

  • AnneCecilia z5 MI
    16 years ago

    Carol, it's a bad year for PM up here in Michigan, too - but mostly on the roses Robiniaquest mentioned: the gallicas first and foremost, the Bourbons, HP's and mosses - they all look terrible. And here too, the monarda and phlox are unusually clean. Did the weather this year promote a slightly different strain? Who knows! I do agree that the Banner Maxx appears to be useless against this infection. Here's hoping this is an anomaly and things will be different (that is, back to "normal") next year.

    Meanwhile, Carol, don't you *dare* rent that bulldozer - I never got the chance to explore your garden in daylight remember, and I hope to back that way again some day! ;-)
    Just keep the saying "This too shall pass" in mind.

    Anne

  • carolfm
    Original Author
    16 years ago

    Cass, thank you for that very concise and easily understood explanation. I can't say that it is exactly what I wanted to hear but it is always better to know what you are dealing with. At least that is what Ann keeps telling me. I think I need that book since I always have so many questions and *issues* in this garden. :-). I'm going to do as Jean advised me, write this whole year in the garden off and hope for better next year.

    Anne, just kidding, I think....Ann and I have been pondering the rental of a bulldozer ever since we got back from New York :-)

    Carol

  • buford
    16 years ago

    carol, I had a lot of PM on my roses this year, and a lot of other plants. My shasta daises,for instance, were gray, not green. I wasn't spraying the roses as much as usual, because it was so dry and there was no BS, so I thought that was part of the reason.

    BUT, it has been rainy here the past 2 weeks and the PM is GONE! I also had an outbreak of BS, but that is another story.

    I think PM survives spray and the best way to manage is to either have rain, or do overhead watering if there is no rain.

    Some of my roses always have PM, no matter what. QE Climber and now ZD, relatively new to my yard, seem to always have it, at least on the top leaves.

  • jean
    16 years ago

    Carol and Ann,

    I am convinced that this year's unprecedented display of PM is related to the freeze followed by drought. Not to put too fine a point on it, but this year has sucked. My plan at this point is to only visit the garden either a) at night or b) when drunk. It's not worth seeing in any other state.

    Sunday, despite the fact that I had a brief due, I went outside and absolutely pummeled a rose with a shovel. It was alleged to have been Prosperity although I was never certain. It appeared that the blooms might have been white if they weren't shriveled and brown from thrips and covered in a furry white coating of PM. It has been that way all season and it enraged me to the point where I removed the offender in a fairly violent manner. I left its carcass in the front yard for all the other roses to see. Let that serve as a warning to the others.

    Jean

  • rosefolly
    16 years ago

    My hybrid multiflora ramblers all have PM to one degree or another. It's a double whammy, chlorotic and mildewed. They do every year, even this year when most of my other roses are pretty clean. I forgot about them when I was writing my earlier post because I hadn't been out to check on them lately. Well today I was doing some pruning and tying up, and they look pretty bad. Somehow I managed not to notice this the other day when I was spraying.

    I am really close to a decision to take them out, except perhaps for Violette, which did very well in another location. I may move it back to its old spot and replace the rest with grapevines. Without losing any of my love for roses, I have developed an interest in food plants lately. It started with Tom's tomatoes, then my fruit trees, then the pumpkins. The latest is grapes. But I still love roses best.

    Anyway, thinking about my chronically chlorotic roses that get such bad PM every year made me think that some of you are onto something. Roses that are under stress, no matter what the stress may be, would likely be more vulnerable to any kind of attack.

    Rosefolly

  • buffington22
    16 years ago

    I have only had spotty infestations of PM in the past. This year it was major and on every single rose in my back garden but not in my front border at all! I do think it must be related to the late winter, early spring drought followed by the Easter cold snap. Tho' we didn't go below freezing (temps hovered around 32), it must have confused/and/or damaged some mechanism in the plants that made them susceptible to disease. Finally, ALL of my affected roses have recovered and there is almost no evidence of the PM. Either the heat or unusual July rain have been the remedy. I was thinking of SP my Duchesse de Brabant but she is in full bloom and although blooms are small,they are pretty and fragrant and abundant. I have to think gardening would be boring if every bush was perfectly foliated and covered in blooms all the time! Buff
    PS I have yet to experience JB's (knock on wood!) and hope they stay away. Thrips in spring are my nemesis.

  • georgia_rose
    16 years ago

    This is an interesting thread. It has been an unusual year for PM in our garden also. I rarely spray and apply very little supplemental water. There are a couple areas of roses that have had PM issues every spring and sometimes again in the fall. These areas have had very little PM this spring even with the very dry conditions. The roses were only watered twice April-June. In late winter the past two years I severely pruned many of the roses in these areas (down to 3-4 ft from 5-6, very little foliage remained) concentrating of those with bad PM history. This was in part to address the PM issue, but also to control size in a closely planted area. Most are large 10 year old teas. After pruning, sprayed the canes and mulch with hort oil. Definite improvement last year and even better this year. Don't know if it was the improved circulation, the spray or combination thereof. These had a spring flush and no appreciable damage from our spring freeze. Wish I had recorded the date of the pruning and onset of new growth. There were some roses in these areas that did not get pruned or sprayed for various reasons- size, laziness, time and labor issues, history of resistance.

    Unpruned and in a different area, a found "ditch rambler" growing in a pecan tree had its usual bout of PM although perhaps somewhat milder than past years. Likewise, Pink Soupert and Clothilde Soupert, usually the sole exhibitors of PM in their respective areas had very little. In yet another bed, Louis Phillipe was very clean this year having had fairly drastic prunings winter and fall, the previous two years but no spray, his bed fellows have been clean this year,

    On the other hand, tall phlox that has rarely had PM was thickly coated in June while the roses growing with them have been clear. Due to the drought a dishpan has been reinstated in my kitchen, emptying the dishpan on the phlox has almost cleared out the PM.

    Carol,you have a lovely garden, hang in there.

    Lisa

  • carla17
    16 years ago

    Carol, I had some PM earlier on Crepuscule and Hippolyte. We live in a great region for roses, NOT. I hope you resolve the PM. My big grips now is of course, JBs.

    Carla

  • patricianat
    16 years ago

    Carol, I have had PM on roses that never had it before this year. American Pillar, who is prone to have it, does not. None of my phlox have it which is weird because they normally do. I have probably 200-300 phlox growing throughout the roses here and there, at least 4-5 feet tall and no PM this year. I am just confused, as they normally get it as does AP and yet neither has it this year. It is just a strange year.

    We plan to add skim milk to the next spray routine if and when we have enough moisture to require spraying, and will see what that does.

  • jerijen
    16 years ago

    BERNDOODLE SAID:
    Optimal conditions are warm, humid days without rain and cool humid nights.

    *** That more or less describes our normal weather pattern, throughout much of the year. So while we rarely see blackspot, we live intimately with powdery mildew.
    We've found that most of our Teas and Noisettes, and most of the Chinas, outgrow major problems with mildew as the plants reach full maturity.
    Some, unf., do not. Old Blush, for instance, ALWAYS mildews.
    For the most part, roses which mildew badly, and consistently enough to be truly unsightly don't remain here.

    Jeri

  • anntn6b
    16 years ago

    I downloaded about twelve PM papers from 'the' literature today.
    One talked about the multiple races of PM on roses and how roses from one site in Europe had a mixture of five different races.
    Another mentioned that to study PM infection of roses they used mini roses and cut them back because they were easier to infect when all the growth was new. (This sounds familiar.)
    PM gets studied a lot because it's the major cause for glass house rose crop loss.
    A paper from Israel suggests sprays with very dilute (0.1M phosphate salt) can knock down PM on cucumbers; and possibly on roses. Sodium salts are also suggested, but another paper reports that sodium salts in anything other than very, very dilute concs have phototoxic side effects. As do products like canola oil.
    The studies of temperature/humidity/ lag in infection development leave me wondering how we've avoided PM before.
    And what we should be doing to clean up our plants before fall and next spring?
    I think I need to cut my big ramblers way back to get a lot more air in; to spray what's left with ???sulphur???foliar feeds????and maybe even baking soda come early fall.

    I did mention Jean's solution to Larry; I think some of our shovel's have disappeared since we got home.

  • carolfm
    Original Author
    16 years ago

    Ann, we spray with lime sulfur every winter to knock back the BS so I would think that if sulfur were going to work that it would have minimized the PM this year?? We have always rotated sprays but maybe we need to add in the Compass this year?? Right now I am at a loss with how to deal with this and I guess it will be trial and error. If you find out anything else in your research......I have read all of these comments and it is amazing to me that so many people have had a similar experience in areas where PM is not something "we live intimately with" normally. I am aware of what the optimal conditions are, what has baffled me is the continued growth in the absence of those conditions. Cass' explanation clarified that.

    Now Jean, that is just hilarious and quite true. We try to only look from the deck and at dusk, it helps. Less light and a little distance improves the look of the garden tremendously.

    Carol

  • michaelg
    16 years ago

    I'll repeat Meg's advice. When her Gallicas started to get moldy, she sprayed them with full-strength or even dormant-strength Wilt Pruf.

  • anntn6b
    16 years ago

    Carol,
    We didn't spray Limesulphur this winter because new growth had already started in late December and I didn't want to burn it. In retrospect, that chemical burn wouldn't have been a long term problem.
    The paper that talked about cutting back the minis severely to get fresh new growth because it was easier to infect it...I think that was the optimum way to infect a lot of roses quickly.
    There are a lot of biocontrols out there being tested on PM on roses, and most of them didn't mention strobilurins (the word that shows up with compass and the other biocontrol).
    I've got a couple of gallons of Mills Easy Feed which can be used as a foliar feed, and I think I'm going to use it at a T. per gallon to see if I can knock down the PM that's still on some of the VW Bug sized ramblers. And then I'll wait for rains.
    My rust infected apple trees will be getting micronized sulphur. But the one at the very end will get easy feed to see if K and P knock the rust out better, or at all. Thank heavens apple rust doesn't move to roses.
    It's going to be a fun week.

  • berndoodle
    16 years ago

    I'll repeat my post from the Roses forum, from the article on PM from the Encyclopedia of Rose Science:
    You need to rotate fungicides using different modes of action. PM spores are clones that can number in the millions in a bad outbreak. Those conditions are perfect for the development of fungicide resistance, one mutation out of a million being decent odds. The recommended rotation is strobilurans, on one hand, and older, broad mode of action fungicides like bicarbonate salts, copper compounds, sulfur or horticultural oils. The Compass label specifically recommends every other spray rotation for PM.

    Unfortunately, most of those older, broad mode of action fungicides can be a problem in high summer heat, although...I've read that superfine horticultural oil is supposed to be okay at higher temperatures than we think. I don't want to do the beta testing at 98 degrees on my roses. Certainly adding Serenade into the rotation would help out. Google horticultural oil and phytoxicity for studies on superfine horticultural oil and high temps.

    If you can get down to the to part of this IPM note where it evaluates the various broad mode of action fungicides, much of the detail is there. These oils and sprays are very effective. I am not a fan of copper compounds, for a coupla reasons -- leaf spotting, phytotoxicity, danger to the sprayer. The vineyards use micronized sulfur, blowing it out of the back of big machines that look like a combination fan-cement mixer. It must work: it's a multi-billion industry in this state alone. And if your temps are moderate, Eco-Erase, jojoba oil, is a wonderment. It will knock PM dead and leave you with shiny leaves and no white fly or fungus gnats to boot.

    Realistic expectations: damaged leaves never "get better." Even an eradicant spray (one that kills existing PM on the surface of the leaves) won't renew already damaged leaves. And if PM got to the point that it penetrated the leaf surface, once a spray kills it, you will still see leaf damage.

    P.S. Full disclosure: I don't spray any more. It's easier to get disease resistant roses than new lungs.

    Here is a link that might be useful: Broad mode of action PM fungicides

  • albertine
    16 years ago

    Ann, I was wondering if your back yard clean plants have received any overhead watering that the farther afield plants have not. How about just supplemental water? That is so fascinating.
    I have that a Crepuscule that is covering about 12 feet of fenceline - at one end it looks clean, on the other, pretty mildewed. It looks much better overall since I have started hosing it down, but way too many other factors to conclude much. I remember Paul Barden saying he thought it helped to wash them in the morning. So far I am mentally much happier after taking Jeri's advice and chucking all that were bad and hosing the rest regularly. Leaves still look puckered but at least they aren't all white.

  • carolfm
    Original Author
    16 years ago

    Okay, Michael, I have reread this thread three times now trying to find Meg's advice...have you tried this?

    Ann, every week is a fun week lately. Obviously, the lime sulfur didn't make much difference here.

    Cass, I know I can't make the old leaves better :-), I would just like to stop the PM on the new growth. Thank you for the additional information. I will read all of it today.

    Albertine, these are not "bad" roses. These are roses that have been in the ground for years and never suffered from PM. If they had been a consistent problem, they would have been long gone. I certainly wouldn't dig up every rose that had PM this year since they have never had problems before! We have, as I mentioned before, been hosing the roses off and noticed "some" improvement.

    Carol

  • michaelg
    16 years ago

    Carol, Meg is a former poster from upstate NY, tremendously experienced and wise, and a nationally known rosarian. If she said it works, then it works. I said "I will repeat" because she posted it several times. Sorry for confusing you.

    I haven't tried it because I haven't had terrible mildew since I read the suggestion years ago. Dormant strength anti-transpirant might be hazardous in hot weather because it reduces the plant's ability to cool itself. It would probably retard growth some. I don't think regular summer strength would be a problem.

  • carolfm
    Original Author
    16 years ago

    Thank you, Michael. I must have missed those posts, or else PM wasn't a big problem at that time so the information didn't "stick" in my brain. I have Wilt Pruf so it would be easy enough to try it at the summer strength.

    Carol

  • patricianat
    16 years ago

    Michael, Carol, I have used Wilt-Pruf with my spray that I did in early April. I have not sprayed since, as we have not had any fungus (sotaspeak) secondary to the drought. I am going to spray this weekend, as I see a return of blackspot with the shower we got last weekend. Perhaps this is the reason mine has not been rampant, since I have sprayed at least once with Wilt-Pruf this year. It seems the roses which normally get it, however, have not this year, which includes SDLM and American Pillar. No PM on my phlox which is "not normal." They normally have it when nothing else does. I will check the zinnias. I have not noticed them as they are just about to get started.

  • anntn6b
    16 years ago

    I also have PM on weeds that normally look as good as weeds can look.
    My back yard healthy roses are at the very top of our hill and have the most rainrunoff (as opposed to accumulation) of any spot in our gardens. And both Tausendschoen and American Pillar are in the shade of walnut trees.

    When Compass was first introduced in our part of the country, the one thing that was emphasized...above all other things....was to limit spraying to four times a year or risk emergence of resistant fungi. Now for them to suggest every other spray...wonder of wonders.

  • berndoodle
    16 years ago

    Ann, I love that. I got a good belly laugh from your weeds. I wonder why so few of the state extension or IPM websites mention anti-transpirants for PM. Nothing impressive in the way of studies on roses other than one that showed Cloud Cover didn't work any better than daily washing with water.

  • carolfm
    Original Author
    16 years ago

    Ann, that is funny about your weeds :-). I also remember reading a few years ago about the need to limit the number of times you sprayed Compass.

    Patricia, that is interesting. It certainly won't hurt anything to spray wiltpruf. Maybe it will help!

    Cass, I tried to find Encyclopedia of Rose Science last night...holy, moly that thing is expensive!!!

    Carol

  • rozannadanna
    16 years ago

    Carol, if you rmember about 3 years ago we had that horrible, horrible hail storm that damaged so many of my roses. I haver had PM but after that I had it everywhere - looked like the garden had been "floured". My theory was that PM usually hit the youngest leaves the worst in early spring but since my roses had to put out completly new sets of leaves - well they were young and therefore susceptible to the PM. I have a feeling that your hard Easter freeze did the same thing to many of your roses - they dropped their leaves - were weakened by the stress of the freeze and having to use energy to put out new leaves. Some of the roses, own root, actually died dead as a doornail almost immediately.

    Here in denver I don't have to deal with bs - not enough moisture in the air for any to survive but I do see PM - not bad but it's there and because I have to water constantly - morning and night - the sprinkler on the leaves seems to keep it at bay. Actually bought a couple of roses from a greenhouse that doesn't spray and no overhead watering, every pot has a dripper in it and those roses had some PM but after putting them into the garden and sprinkling them every day it is almost gone.

    Roses in Denver are a whole nuther thang than roses in East Texas.

  • carolfm
    Original Author
    16 years ago

    Hey Rozanna, I do remember that hail storm! I haven't lost any roses from the freeze yet, but some of them are still struggling and down to a cane or two. On the whole, most of them are starting to look better and putting out new growth. It would certainly help if we had some rain (finally had a little last Sunday, yea) but in the meantime we continue to water and wash off the foliage. I would like to grow roses in an area with no BS or JB's just once before I die :-).

    Carol

  • rozannadanna
    16 years ago

    no bs and no jb's but think cold, dry, dry. And I guess Tx is getting all the rain - drought for the last 3 or so years there and it is still raining at my place so Mother tells me.

  • anntn6b
    16 years ago

    At least we're not alone in this.
    Rozanna has 'normal' rainfall.
    But the map doesn't show the areas of waterlogged misery; it just lumps them in with normal.
    There's not a lot of rainfall out there washing PM spores off of plants.
    We're getting rainfall in 0.2" increments. It barely wets the surface of the ground, but the non-gardeners on the local TV stations are so happy for rainfall that's measurable. Even if it doesn't do anything but make the Johnson Grass grow.

    Here is a link that might be useful: This week's bad news drought map

  • albertine
    16 years ago

    Sorry, Carol, I didn't mean to imply that we were dealing with the same situation. The sheer irrationality of your outbreak is fascinating - it seems like that cold you all experienced must have something to do with it, but who knows why, and why is the problem continuing this late in the season?

  • carolfm
    Original Author
    16 years ago

    Albertine, whew, I thought you were suggesting I dig the PM'd roses up. If I did, I wouldn't have but about 4 roses left after this year. :-). I'm sorry if I misread your comments. I agree with you, roses that cause me heartache with their disease problems (after much patience, moving to new locations, etc.) are deemed to be unhappy in my garden and have to find new homes.

    Ann, the frustrating thing is that it has been raining all around us, and not here. One day it rained on the other side of the street but not at my house. That was painful to watch!

    Carol

  • michaelg
    16 years ago

    Carol, I've been enviously watching all the radar blobs over upstate SC enviously. You must have had terrible luck to still be dry. Actually there has been a fair amount of rain in western NC, but I haven't had any. I had adequate rain for one week in mid-June, otherwise nothing significant since May 5. The radar blobs approach and then dissolve at the last minute, with just enough afternoon spatter to spread blackspot and botrytis.

  • carolfm
    Original Author
    16 years ago

    Micheal, we got two glorious inches of rain last Sunday. Other than that, a few sprinkles that set the blackspot off and running and no measurable amounts of rain. We watch the radar too and see a huge storm heading for us and it splits and goes around both sides of us! It was sort of funny at first but it's no longer amusing. Those two inches are the only significant rain we have had in months. Lots of rain in other areas of the upstate, though. I thought you guys were getting a lot of rain.

    Carol

  • patricianat
    16 years ago

    Carol, that promise of growing roses without disease is reserved for those who make it to Heaven. I know there have to be perfect roses there; it's the thing that regardless of what we do in the south, we never have that perfect climate. Yeah, I'm looking forward to that day, of seeing rows and rows of clean roses that are thornless and require only sniffing and arranging in vases of silver and gold. :)

  • michaelg
    16 years ago

    Carol, the Asheville weather station is 25 miles away-- they've had 4" more than me since June 1, amazing as that sounds. I did get a half inch yesterday, first significant rain for a month.

  • anntn6b
    16 years ago

    I got rain yesterday. The storm snapped the base of a 12 year old Red Delicious apple tree, taking down the fence to it's north and with it the spigot that I used to use to water the roses in back. The storm ripped part of the roof off of DH's engine shed and dropped other limbs. But not the remaining third of the big maple in the back yard (the one with the four foot basal diameter)that lost two massive limbs several weeks ago on a calm day.
    Yesterday's winds were almost a carbon copy of the conditions when we had the tornado.
    I am becoming more and more thankful for my OGRs that slog along regardless.
    There's one perfect bloom out front on SdlMRougeNot that is probably an Autumn Damask. Just there, glowing with pink goodness.

  • jean
    16 years ago

    Ann,

    I am amazed that you had such severe weather. As usual, nothing here but sun, heat and humidity. I dread the water bill. I am contemplating dancing naked at midnight and sacrficing something to get rain. We are now 17" behind for the year.

    Jean

  • carolfm
    Original Author
    16 years ago

    Patricia, I think you are correct. :-)

    Heavens, Ann, if that wasn't a tornado, it was at least a micro burst. We have a lot of micro bursts here. Knocks down trees, rips off roofs, all sorts of damage.

    Michael, they forecast and report our weather from the Greenville/Spartanburg airport which is at least 30 miles from us and their reports of rain fall, high temps, low temps, any of it, rarely reflects what is actually going on in our area. The east side of Spartanburg has had several inches of rain and some sections of the west side have had rain but it has been very scattered. It seems like the same areas get rain over and over and the same areas stay dry. So not fair. We really have had bad luck in the rain department this year. About 3 years ago it was the opposite. It seemed like a rain cloud hung over our house for months. It rained every day and would be dry half a mile from us.

    Jean, maybe you could sacrifice manbearpig?? We got our water bill....yikes!!

    Carol