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kitasei2

spraying for blackspot

11 months ago
last modified: 11 months ago

I began spraying with baking soda and New Dawn early in the season but soon after flowering half of my roses are still totally defoliated. In desperation I bought a copper spray. How do those of you who spray do it economically? It feels like such a waste to be spraying bare stems!


By the way, most of my roses were supposed to be disease resistant - Plum Perfect and Quick Silver?

Comments (21)

  • 11 months ago

    Do not waste your money on anything deemed “organic” if you want black spot control in a heavy black spot pressure area, they are not effective. Spray fungicides if you are going to spend your time and money, they are effective if done correctly. The other option is to keep testing varieties until you find those that do not need it in your yard. In my yard Quicksilver and Plum perfect also defoliate while Florentina, laguna, earth angel and several other Kordes are perfect without ANY Spray. I know Quick Silver is perfect for Moses so very location dependent.

    kitasei2 thanked dianela7analabama
  • 11 months ago
    last modified: 11 months ago

    I went through the "organic" thing several years ago. Same results. I have 115 roses (of all types), so I have a significant amount of $$$ involved in my garden. I use BioAdvance Disease Control every 2 weeks. It works for me. I go organic where I can (feeding) but I'm not purest. I take care of my investment.






    A healthy bush produces good blooms.

  • 11 months ago

    I do not want you to think there is no hope. You can have a happy beautiful rose garden without spray but it takes some work (lots of work). Here are pictures of my 100 percent no spray garden this year.

    It didn’t happen easily tho. In my previous garden I had more than 400 roses and after a few years of testing I have managed to find some varieties that seem to do very well no spray. It is still trial and error but it is working out for me. If no spray is what you prefer you can certainly do it.



    spring









    this is from this week






    kitasei2 thanked dianela7analabama
  • 11 months ago

    OK i get it but how can you do it affordably? Do you buy it in bulk?

  • 11 months ago
    last modified: 11 months ago

    nope fungicides are expensive i do not have any good ways of getting them cheaper, bulk would def help. The only cheap alternative is to not spray.

    kitasei2 thanked dianela7analabama
  • 11 months ago

    I've found "local" advice on how disease resistant roses truly are to be fairly accurate. "Local" being roughly from D. C. to Boston, east of the Appalachians. Unfortunately, there aren't as many regular posters from there as there used to be. Sometimes you can scare a lurker out of hiding, but only if the thread hasn't been overrun by posters from other places. It used to be posting in the New England forum was a good idea, but the traffic isn't there anymore.

  • 11 months ago
    last modified: 11 months ago

    For me it is trial & error .A lot of so called disease resistant roses , don't do well for me in Florida's high heat & humidity . Still I spray all year every 2-3 weeks .

  • 11 months ago
    last modified: 11 months ago

    Well here in New York I can say that Florentina stands out. Are there any others that come close? Mad gallica?

  • 11 months ago

    I have hardiness issues you don't, so most of my best roses are once bloomers - R. hugonis, R. primula, Ispahan, Baltimore Belle, Karl Forster. For large repeating roses, it is hard to beat Captain Samuel Holland for blackspot resistance.

    kitasei2 thanked mad_gallica (z5 Eastern NY)
  • 11 months ago
    last modified: 11 months ago

    Kitasei2,

    How did you determine that fungicides are expensive? They aren't, by my estimation, and I am a man of extremely, extremely modest means. A bottle of Immunox is $15.99 on Amazon. It's a pint size, 16 oz. 2 T. per gallon of water means 16 gallons of spray per bottle. At two week spray intervals, using a gallon of mix per spray, you will have sufficient Immunox for 8 months. If you spray accurately, you will be amazed at how little mix you need per spray.

    Bayer Fungicide is Amazon priced, $18.79 per quarte, 32 oz. Same dosage rate as Immunox, 2 T. per gallon of water, will last for 32 spray sessions. That's 16 months if sprayed every two weeks.

    Both give excellent control for black spot.

    Quick Silver and Plum Perfect are considered highly black spot resistant, but under stress, anything can happen. They are not ADR winners.

    If you're willing to spray, you can grow any rose that you want...even Angel Face and Double Delight, black spotters to the nth. degree, but under a faithful spray program, with the spray applied correctly, they will thrive for you. However, if you fall lax in care: watering, weeding, fertilizing, dead heading, etc., beware of black spot showing up.

    If you're not willing to spray, only ADR winners are reliably black spot proof just about everywhere. Earth Angel, Summer Romance, Grande Amore, Dee-Lish and Oh Happy Day are ADR winners that I have grown/or still grow that are personally recommended. Each has its strong points and weaknesses otherwise, but regarding black spot they are pretty bullet proof.

    Ping Lim has come out with a line of black spot resisters called True Bloom.....Give them a try. True Bloom True Inspiration is doing very well for me.

    Moses

    kitasei2 thanked Moses, Pitt PA, cold W & hot-humid S, z6
  • 11 months ago

    ADR winners aren't necessarily resistant to blackspot here. I've seen them completely defoliated at the beginning of August, which is much better than usual, but not great.

  • 11 months ago
    last modified: 11 months ago

    The ADR winners are growing under severe stress if defoliated by August. Multiple negative factors would be in play, especially very poor air circulation or extreme water deprivation to name just two.

    Moses

  • 11 months ago
    last modified: 11 months ago

    Moses I am always after ADR winners as I tend to have very good luck with them but I have to disagree on this regard. My Quick Silvers are not under severe stress because they are growing right next to the other plants that are not defoliated. We get over 50 inches of water naturally and now during the summer which is our driest time I water adequately, it is still defoliated. Flamenco Rosita, Mel’s heritage and many others including 2 Bathshebas have great looking foliage right next to Quick Silver. They simply no resistant to whatever black spot strain I have in my yard.

  • 11 months ago

    The extreme stress they are growing under is growing here. They don't get pampered, but they shouldn't have to be.

  • 11 months ago
    last modified: 11 months ago

    IMO its hard to recommend a certain rose because they differ in disease resistance etc etc from garden to garden... I just take a recommendation trial & error and hope for the best...

    kitasei2 thanked jim1961 Central Pennsylvania Zone 6b
  • 11 months ago
    last modified: 11 months ago

    Black Spot season started very early this year for me. I use chemicals once a year after winter and bio fungicide for the rest of the season. Not counting my new additions (40+ roses), I can say that in my hot and humid climate, these roses are doing extremely well:

    • Olivia
    • Peach Swirl
    • Augusta Louisa
    • Ashley
    • Summer Romance
    • Rosenfaszination
    • Pompon Veranda
    • Coral Lions-Rose
    • Moonlight Romantica
    • Poseidon

    I bought Kukielski's book out of curiosity, his list of roses is so booooring...

    kitasei2 thanked elenazone6
  • 11 months ago

    Minimal spraying may make a difference. Pat Henry of Roses Unlimited wrote that she sprayed once one year and I assume it worked out for her. My rose friend sprayed three times one year and that was enough. You don't have to be all in or nothing.

    I think spraying small plants makes sense because they need all the help they can get while small . Once established I think they can tolerate some leaf loss better.

    " Optimal conditions for black spot occur when temperatures are in the 72 to 85 degree Fahrenheit range; along with high humidity and water that remains on leaves for periods of 6 hours or more. " So when it's really hot I don't spray much if at all except for my smaller and potted plants. In hottest weather they can be stressed from lack of water too so spraying may stress them more . I hardly ever get defoliated plants and I slack off on spraying in hot weather and I don't spray in winter.

  • 11 months ago

    Moses, thank you for giving me exactly the information I need. I waa buying premixed sprays and going through them in one go.

  • 11 months ago

    Elena

    ITA I browsed through that Kukielski list and thought I’d sooner abandon roses and make do with petunias and begonias.

  • 11 months ago

    Personally I like Kakielski’s book and don’t find his lists boring but I also always assumed it was aimed at folks that want to explore their options outside of just KOs for healthy roses in the garden. For that use case I think he does a great job.

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