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most blackspot resistant hybrid tea?

Posted by sabalmatt_dallas Z8 Dallas (My Page) on
Fri, Jan 1, 10 at 15:02

Hello,
I want to find out what you think the most blackspot resistant hybrid teas are? I've read that Memorial Day and the Radiance clan are very resistant. What is your experience?
thanks


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RE: most blackspot resistant hybrid tea?

  • Posted by maryl Z7 Okla. (My Page) on
    Fri, Jan 1, 10 at 16:00

I don't know of many roses that stay clean in our climate (and Dallas isn't that much different then mine). Our long growing season coupled with the high humidity can take its toll on many roses that in a more northerly climate might do better. Belinda's Dream is a shrub with HT style blooms that's reported to be B.S. free. I spray, but mostly during prime disease time. During that time if I miss a rose for some reason it is usually the fragrant HT Secret. I never saw any B.S. on it with this hit and miss spray schedule. Gemini is another one that supposed to stay fairly clean with only minimal spraying. The ARS (in conjunction with Texas A&M - I think) is going to conduct field trials starting this year to answer this very question. Maybe in a few years there will be more to add to the list. Sorry, I don't grow the two you listed.


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RE: most blackspot resistant hybrid tea?

It is hard to give any advice unless you are in the similar climate. Here we have a lot of BS and ALL HTs defoliate withut regular spray program, including Gemini, Secret and Belinda's Drean (shrub).
The only HTs that I tried and which keep at least some leaves here are Liebeszauber and Rio Samba (some years).
Olga


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RE: most blackspot resistant hybrid tea?

I agree about Belinda's Dream, but the others mentioned had to be shovel pruned. Rio Samba was one of the worst, but it can have to do with individual roses, nurseries, and particular climate.

I was surprised that Rina Hugo has done well. Traviata is ok, but I don't remember it is HT or FL. The same goes for Frederick Mistral.

Sammy


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I grow Belinda's dream and it has grown well- no BS issues. I grow chinas, floribundas and Earthkind roses without blackspot. The two that get some BS are midnight blue and wild blue yonder.


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Many roses that are fairly resistant on the plains or even the Deep South will defoliate in the East. Belinda's Dream is a mess here, with severe Botrytis petal blight, severe Cercospora spot, and considerable blackspot. Frederick Mistral defoliates quickly. Radiance must be sprayed. Traviata blooms OK without spray but shows a lot of Cercospora and blackspot.

After decades of experiment, I have given up on no-spray for repeating roses except for a few Buck roses such as the HT-like Earth Song and Prairie Harvest. I do have some HTs that stay clean with monthly (as opposed to twice-monthly) spray-- Elina, The McCartney, Mother of Pearl .

Naga Belle is said to be highly resistant. I've ordered it.


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It sounds like you are already growing the roses that perform best here in the Dallas area ... china roses and the roses that are on Texas A&M's EarthKind list. There is a reason there are no hybrid-teas on that list. That list was made for our climate.

Randy


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RE: most blackspot resistant hybrid tea?

  • Posted by maryl Z7 Okla. (My Page) on
    Sat, Jan 2, 10 at 14:39

Michael makes a good point about other leaf spot diseases such as Cercospora causing damage to a rose even if it is considered blackspot free. Every few years we will have an unusual coolish wet summer period and the leaf spot diseases (anthracnose is another such disease) can take off on some of my susceptible varieties. Banner Maxx/Triforene (my spray materials of choice) seem to have little to no effect on Cercospora, so even though the roses may have been faithfully sprayed for B.S. the leaves look ratty all the same. Took me awhile to figure that one out.


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RE: most blackspot resistant hybrid tea?

Maybe something on this list will help you

Here is a link that might be useful: one of them list


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RE: most blackspot resistant hybrid tea?

  • Posted by jont1 Midwest 5b/6a (My Page) on
    Sun, Jan 3, 10 at 4:46

My most disease resistant roses of the 300+ I have:
Voodoo
Mother of Pearl
Paul Ricard
Our Lady of Guadalupe
Savoy Hotel
Westminster Pink
Pasadena Star
Sunset Celebration
Vavoom
About Face
Liebeszauber
Dublin
Pristine
Love & Peace
Octoberfest
Hot Cocoa

John


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RE: most blackspot resistant hybrid tea?

maryl--

It's cooler here with frequent light rain, and Cercospora can be a significant problem all season. Glossy-leaved varieties that are somewhat resistant to BS tend to be highly susceptible. So when, decades ago, I started moving from standard HTs to modern roses that were supposed to resist BS, I just found myself with a new disease problem that was almost as bad.

Triforine (the Ortho rose fungicide) definitely does not work, nor does sulfur. Bayer does work, so I'd expect the similar Banner Maxx to work as well, but I've never used it much.

On most varieties, infected leaves can live for a couple of months, so it doesn't weaken plants as radically as BS does. However, if I don't control it, it will defoliate some plants by August or September. And susceptible plants like Belinda's Dream look bad for most of the season here if not sprayed.


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RE: most blackspot resistant hybrid tea?

  • Posted by maryl Z7 Okla. (My Page) on
    Sun, Jan 3, 10 at 15:13

Michael, I have the Bayer "Disease Control for Roses, Flowers & Shrubs with the active ingredient 'Tebuconazole'. Is that the Bayer product you use on your roses? I see Anthracnose listed under diseases, but not Cercospora. But you say it works on Cercospora as well? I couldn't find much info on what to spray on roses for Cercospora.......And how interesting when you mentioned the shiny leaves. That would be the case in at least one of my leaf spot susceptible roses. I'll have to pay closer attention to the leaves of the other roses should the disease strike again.


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RE: most blackspot resistant hybrid tea?

Maryl, yes, the Bayer Disease Control. Tebuconazole is labelled for Cercospora on many other plants, but maybe it hasn't been trialled on roses. It does work on roses for Cercospora in my experience.

Some susceptible varieties that come to mind are The Fairy, Belinda's Dream. Prairie Harvest, Winter Sunset, Sunsprite, Iceberg, Colette, Traviata, Serendipity, Irish Hope (somewhat), many of the Meidilands-- a list tending toward glossy and BS-resistant. I suspect Wichurana influence is a factor.


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RE: most blackspot resistant hybrid tea?

  • Posted by maryl Z7 Okla. (My Page) on
    Mon, Jan 4, 10 at 16:10

Thanks Michael. Always find your comments and experience most interesting.


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RE: most blackspot resistant hybrid tea?

Elina out of the 40 HT I grew. It could go all summer w/no spray and have all it's leaves. And beautiful too.


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I can vouch for Lafter, an HT by Brownell. I am in BS heaven on Long Island, and it is always in perfect leaf in my no spray, organic garden.

Here is a link that might be useful: Lafter on HMF


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RE: most blackspot resistant hybrid tea?

Of several dozen HT's I have personally grown no spray over the last 10 years, the best has been Sunset Celebration. It will get some cercospora spot and some years a bit of rust, but maintains the majority of foliage and looks good year after year (I've had for 7? years.)

A possible contender? Deep Secret. New to me spring '09 (it came to my attention from several folks on the Antique Rose Forum who noted it was among their most disease resistant HT's.) So far no disease of any kind-no blackspot, no powdery mildew, no cercospora spot, no rust.

Winter Sunset and Marie Curie (both shrubs, not HT's) and Crepuscule (noisette/climber) have excellent disease resistance (here.) Of Austins I've tried, one with best disease resistance is Jude the Obscure, and Molineux & The Prince are both quite good.

My other more disease resistant HT's (but not perfect) would include Bronze Star, Tiffany, and Oklahoma.

I have a very long list of 100+ roses that are NOT blackspot resistant here! Feel free to email me if you want that list-LOL :)

Dawn


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Funny how climate produces such varied results. Michael, Iceberg (a floribunda) blackspotted horribly for me. It's history now. I've actually never seen any rose completely immune to blackspot. the boring (to me) Knockout comes close. But I've seen some on it even. My Belinda's Dream (I know, technically a shrub rose) had significant blackspot when I first planted it but seemed to shrug it off once well-established. And I'll second Irish Rose and Dawn that Elina and Deep Secret have been highly blackspot resistant (not immune) for me. Great disease resistance both. I had one of the Radiance roses as well--Careless Loss--and it was pretty healthy, though I have to say it is technically a hybrid tea but certainly not a modern one and does not have the modern form one usually thinks of for this class. Still a very good rose. Ditto for the old hybrid tea Mrs. Herbert Stevens (pure white).


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count this as another vote for Lafter (though the thorns are somewhat daunting)


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In my eastern Pennsylvania garden, all roses get blackspot if I don't spray regularly. Even KO, The Mayflower, Earth Song and the OGRs. The only exception is my Rugosa.


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RE: most blackspot resistant hybrid tea?

of all the HT roses I've tried, the only one I've grown long enough to recommend is Traviata. It's listed as a HT but, to me, it's closer to a shrub. It probably will need to be sprayed but much less than most and is a very good performer for me.


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RE: most blackspot resistant hybrid tea?

Mike in New Orleans reminded me-yes Mrs. Herbert Stevens is very disease resistant here, too. Nice fragrance & shade tolerant to boot.

FYI she does NOT have that exhibition/high centered bloom & typical bolt upright HT growth habit if that's what you're looking for/expecting.

I bought mine at Vintage Gardens.

Here is a link that might be useful: Mrs Herbert Stevens


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In St. Louis, my Memorial Day had very few leaves left by August due to blackspot. I do not spray.

Teresa


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Midas touch is almost totally resistant for me here is Mesena,Ga.

Vernon Johnson
Mesena,Ga


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Mike_in_NO-- agreed, Iceberg is a bad blackspotter all over the East and South.I wasn't intending to recommend it but to comment on its problem with Cercospora.


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RE: most blackspot resistant hybrid tea?

  • Posted by jont1 Midwest 5b/6a (My Page) on
    Sat, Jan 16, 10 at 3:47

I see lots of cercospora here rather than blackspot but alot of folks don't know the difference and think it is blackspot. Mancozeb is also supposedly good for cercospora but I use Mancozeb every time I spray and I haven't seen it do a thing for it on my roses.
Same goes for the red-spotting I see on whites and light pinks--Crystalline seems particularly susceptible to it. I can't think of the name of it just right now for some stupid reason... Most of my Crystalline blooms look like they have measles all the time. Memorial Day tends to get it as well.
I do spray with a rotating mix of Honor Guard (generic Banner Maxx), Compass, and Funginex always mixed with the Mancozeb flowable at the lowest rate. It seems to work well for me and I generally don't have much fungal issues so long as I don't get behind like I did this past year. I ended up hospitalized many times for long periods this past Spring and so the spraying and care got behind and then I was fighting it all year long.
Quite frankly, I think that overall plant health is the most important aspect of disease resistance a rosarian can work on. Start your new growing season on the right foot by being sure to dormant spray to kill any overwintering fungus spores late in the winter while the roses are still dormant. I prune them and then spray when there are no leaves and am very careful to spray the ground around the roses as well as that is where alot of the fungal spores hide and then get splashed up with water or blown up by wind onto the roses to start the re-infection all over again. I start spraying as soon as I see the first leaves starting to form on the roses and then continue spraying every three to four weeks the entire growing season and then dormant spray after the roses go dormant in early winter and then again just before they break dormancy in the Spring. Believe me, this is super important to start out healthy right from the start!!
I also start fertilizing using my drip irrigation systems for each bed with the EZ-FLO Fertilizer Injector so I can water and fertilize with my own jungle juice fert concoction once per month. I also add an alfalfa based dry fertilizer under the roses every 6 weeks--2 cups for large roses and 1 cup for miniatures for each bush. I also spray with Messenger and Superthrive about 6 times during the growing season which also lends to leaf health and thus disease resistance. But, Messenger is no longer being produced, so that's a bum deal as I like it.
I know this sounds like alot of work, but I figure that if I am going to grow roses I am going to put in the work, time, and effort to make them as beautiful as possible. Besides, I enjoy it.
All this is worth it to me. I had a master rosarian visit my gardens this past Fall and he accused me of growing my roses on steroids because they were so large and healthy and covered with blooms. Not to brag too much, but I think most of all my roses grow about 1' taller than most because of the work I put into them. And, bigger rose bushes mean more and bigger flowers and that is what it's all about in the long run.
John


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RE: most blackspot resistant hybrid tea?

Thank you John, for all of this information.I am not a new rose grower, but my roses(120) could be better!!! This post will be very helpful to me this coming spring. I appreciate everyones helpful posts. Lesley


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RE: most blackspot resistant hybrid tea?

John, the name you were thinking of for the pink fungus freckles on petals is probably botrytis blight, and I don't know a good remedy.

I'd like to add a suggestion -- Roundelay, a dark red grandiflora, usually blooms in threes with hybrid tea type flowers and I haven't noticed any disease problem in the twelve years I've grown it. It is listed on HelpMeFind.com as available from Heaven Sent roses.

Paul Barden, the hybridizer, who lives in a climate where blackspot is a problem says of Roundelay, "here in my climate it is immune to blackspot even when not treated with fungicide. It is a shapely shrub of about 4 X 4 feet and blooms in clusters of deep garnet red 4" blooms."


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RE: most blackspot resistant hybrid tea?

  • Posted by maryl Z7 Okla. (My Page) on
    Sat, Jan 16, 10 at 14:43

Ditto Jon on your experience with Mancozeb not controlling Cercospora, which is why I was happy to hear from Michaelg about the Bayer product (Tebuconazole) doing the trick.... I think the main thing to try to accomplish on BS is prevent it from ever occuring. For example: I went 3 years with hit or miss spraying on a particular HT I had and never experienced so much as a spot of BS. I was so impressed with it's disease resistance compared to some of my others that I kept pulling back more and more on spraying it just to see how little I could get away with. One fall (great temps for BS in our climate) I didn't spray at all and it finally succumbed to BS after a couple of months. Since then, despite good cultural practices, it has been one of those roses I must keep an eye on. From low spray to high spray in other words. The lesson to me is that in my climate, some spraying is necessary. The question for me now is which roses are low spray and which are high spray. I'm really trying to eliminate as many high spray roses as possible and, contrary to the myth, Hybrid Teas aren't the only disease magnets out there.


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RE: most blackspot resistant hybrid tea?

Pope John Paul II


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RE: most blackspot resistant hybrid tea?

  • Posted by jont1 Midwest 5b/6a (My Page) on
    Sun, Jan 17, 10 at 0:18

Thanks for the info petaloid. botrytis blight is the name I was at a loss for!! Botrytis really makes some very beautiful blooms very ugly in a hurry and it is so hard to remedy once it gets a foothold in a rose. My Crystalline seems particularly hard hit. I wonder if it is more prevalent in the reds than we think but it is just masked by the disease being the same color as the bloom. So, if anyone knows of a good cure for botrytis blight I would appreciate a heads up about it for sure.
Cercospora is another fungal that is so hard to remedy. I would venture that most folks think they have BS issues with their roses when in truth it is cercospora because they look so much alike. Some roses that are supposed to be BS resistant may actually be so but are very susceptible to the very different organism causing cercospora.
Also, thanks for the heads up on Roundelay. I am always on the look for good breeding roses that are very disease resistant as well as beautiful and this one looks like both. I especially appreciate seeing the whole bush shots of roses on HMF like the one posted of Roundelay. Sometimes people forget just how important the bush quality is to the rose. Let's face it, there is lots more rose bush than bloom and it is the structure the whole rose is based on. If you don't have a good bush you won't have lots of good rose blooms to enjoy.
Roundelay is the ancestor of many good breeding roses that are beautiful as well. That is quite rare in the world of the older roses as disease resistance didn't seem to be a focus of many hybridyzers. They seemed to think that fungal disease and roses were a team and nothing could/would be done to improve it. Thankfully some very good hybridyzers did address the situation.
John


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I was once on the same quest as you for a blackspot-immune rose. I never found one completely immune except for (sometimes in some locations) Knockout. But I wanted to have a beautiful rose garden of HT's and floribundas without spraying. When I realized I could not find blackspot-immune roses, I accomplished my garden-without-spraying by extreme diligence in deadheading and hand-removal of all blackspotted leaves. But the time it took every week was just too much. I finally succumbed to temptation and sprayed the garden "just this once" and immediately was addicted to the beautiful green foliage, the healthier fuller plants, the better flowers, and the reduction of time that spraying took in contrast to the time that my grooming regimen took. I still groom and deadhead and remove diseased leaves, but there are a lot fewer of them, and my roses are doing wonderfully. It is still a good idea to look for resistant varieties; I never consider a rose that growers/Help Me Find or anyone will admit are disease prone. But I am sorry, they ALL get some blackspot in the humid south.


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hi! I just wanted to comment on Memorial day for you. I would not recommend this rose for our zone. Although it gets very little blackspot is also gives very few roses, the roses don't come out well during the heat of the summer, and thrips love them. This has been my experience and the experience of several others in my area too.

Sunni


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A light mist of Daconil will take care of Botrytis, but I rarely use it, due to the potential for eye damage.


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MichaelG posted a formula to treat botrytis a few years back that worked wonders. The chemical base was calcium nitrate or some other form of soluble calcium if I remember well. It had to be sprayed on the rose blooms before they opened. Worked like a charm, the material was cheap and not dangerous like Daconil or the extremely expensive stuff like Degree (??). The best compound is not available here in the south but for those in the north who still have snow can be bought now because it is used for melting snow - I just cannot recall the name, since I never saw it here. Maybe calcium sulfate? (???)

Michael, if you have the article or the summary handy, would you be kind enough to re-post it? I know that I saved it somewhere but it will take time till I find out where.


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RE: most blackspot resistant hybrid tea?

Here's the calcium for botrytis thread mentioned above by ceterum. I wonder if Michael has any update on this info or any more experiments to report on.

Kathy

Here is a link that might be useful: New & Improved Calcium for Botrytis Thread


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I think the calcium does help, but I haven't done controlled experiments, nor am I aware of real experiments in the garden as opposed to the greenhouse and cut flowers. The problem is, you have to apply it frequently. If you're interested, try it weekly through the peak of the first flush when rain is expected.


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Most of the newer varieties of Kordes' roses, including HT's, are remarkably resistant to diseases. Not immune, but exceptionally resistant.

Kordes no longer sprays in their growing/trial fields and they only select the roses that exhibit high disease resistance.

Two very BS resistant Kordes HT's are Grande Amore 2004 and Eliza.


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There were a few former floral white roses that were botytis free most of the time but Crystalline was always dotted with pink spots or rings let it be spring, fall or 100+F during day but the the over 80% night humidity and morning dew guarantee botrytis blight almost all season for susceptible varieties. Actually, I might even get rid of Crystalline.


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Climbers for the South

  • Posted by alice 7B Upstate SC (My Page) on
    Thu, Mar 18, 10 at 21:15

I can't make up my mind about which rose I want for my arbor. It has to be disease-resistant because it's very hot and humid in the summers here. I love the antique and Austin style roses. I had Eden at another house here, but it balled. Red Eden is reputedly disease-resistant, and I am leaning toward that, though wondering if it balls too. What about A Shropshire Lad or Golden Celebration as climbers?


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RE: most blackspot resistant hybrid tea?

  • Posted by alice 7B Upstate SC (My Page) on
    Thu, Mar 18, 10 at 21:19

Sorry, I didn't mean to post to this thread!


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RE: most blackspot resistant hybrid tea?

From my experience, Memorial Day has been the best black spot resistant rose I've ever had. It blooms constantly and I love it. Other roses I have had that have issues include:

Frau Karl Druschki - easy to take cuttings from, nice blooms but it does get BS very easily.
Peace - never had much luck with this and it really gets BS - can weaken a plant to death.
Double Delight - same as Peace.
Chrysler Imperial - Blooms and fights BS but drops leaves everywhere.
Mr. Lincoln - blooms and will drop every leaf that has BS.
Whisper - One of the worst roses I've ever tried to grow. nice blooms but BS will kill it.


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Golden Fairytale- No BS in 4 years now. Slight late season mildew in Sept./Oct. Almost always in bloom.

Eliza- No disease in 4 years now.

Grand Amore- slight affliction to BS in late season in 5 years now. No mildew.

La Perla- no disease in 2 years.

Beverly- above average disease resistance, but not perfect. Some mid to late season BS and late season mildew. Huge, long lasting and exceptionally fragrant blooms make it worth it regardless.


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