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jujujojo_gw

How to deal with black spots

jujujojo_gw
9 years ago

My mini-roses seem to be very vulnerable to black spots. If it rains a lot, the black spots grow on all leaves. The black spots kill leaves pretty fast. Do I really have to buy some kind of spray?

Comments (16)

  • seil zone 6b MI
    9 years ago

    Minis do tend to be black spot magnets for some reason. Maybe it's because they're leaves grow so close to the ground where the spores are. If you have to have spot leaves the only thing you can do is spray. Look for the Bayer Rose Disease Control, NOT the 2 in 1 or 3 in 1 products.

  • jujujojo_gw
    Original Author
    9 years ago

    Posted by seil z6b MI (My Page) on Sat, May 31, 14 at 22:02

    Thank you for the advise. I have already asked and learned that red wine vinegar appears to be a cheap solution. I have sprayed yesterday, the leaves do look better already!

    On the other hand, can we develop some black-spot super resistent mini-roses?

  • diane_nj 6b/7a
    9 years ago

    The only use of vinegar I have heard of is being used as a herbicide (weed killer). Be careful.

  • seil zone 6b MI
    9 years ago

    I second Diane's warning! Vinegar is not a fungicide but a herbicide as far as I've heard. The other thing you need to remember is that if a leaf has already been infected with the fungus spraying it with anything will not matter. Eventually that leaf will spot, yellow and die. Most fungicides only help prevent clean leaves from not getting infected.

  • jujujojo_gw
    Original Author
    9 years ago

    Yeah, after tries, it seems vinegar does little.

    For me, the most effective way is to stop rain from falling on the plants. Sometimes, being greedy with too many potted roses can be punishing ...

  • Tommyotommy
    9 years ago

    Hello all,
    I'm in south Louisiana and blackspot is a major problem in our climate. I'm currently using a spray by Ortho. Just switched from Fertilome so the jury is still out haha

  • seil zone 6b MI
    9 years ago

    On here the most recommended spray for black spot is the Bayer Disease Control for Roses. Do NOT get the 2 in 1 or 3 in 1 products. They are not as effective and have things added that you do not need or want.

  • Tommyotommy
    9 years ago

    I saw the Bayer spray but had never heard of it before. I'll try it if the ortho doesn't work. Thanks

  • jujujojo_gw
    Original Author
    9 years ago

    Seil and Tommy, I have never seen any of the products in local WALMART. What stores carry them?

  • Tommyotommy
    9 years ago

    I had to order the ortho online from Amazon. It's a concentrate you mix with water. The Bayer spray I saw at a local mom and pop nursery. Very pleased so far with the ortho so far. Don't know if it's a coincidence but not one of my 10 miniatures has anymore blackspot... knock on wood. I've only even sprayed it once too.

  • jujujojo_gw
    Original Author
    9 years ago

    Posted by Tommyotommy none (My Page) on Mon, Jun 23, 14 at 8:45

    My mini's did not have black spot until I moved them to the backyard. Our neighbour has a huge and disease resistant rose with fat, dark and shiny leaves. That is the source of the disease.

  • seil zone 6b MI
    9 years ago

    Black spot spores are everywhere, the air the soil, the plants, everywhere. A change in location may have just put them in the right conditions for it to show up.

  • Tommyotommy
    9 years ago

    Knock on wood here y'all but none of my roses have blackspot anymore sine I've been using the ortho. I don't wanna jinx it.

  • dan_keil_cr Keil
    9 years ago

    The only chemical that will kill the blackspot spores is Dithane/ Manzate/Mancozeb.. It contains Zinc and Manganese. It works great to clean up a infection. Then go back to a regular spray . 95% of all roses will get blackspot and it's easier to PREVENT it instead of deal with it once you have it! I'm sorry there is no proven organic Disease control

  • BethC in 8a Forney, TX
    9 years ago

    So Dan, how soon should I start a spray program. I am in zone 8a. We usually have our last frost the first week in March even though this weekend we are having ice and sub freezing temps. Our rainy season starts toward the end of March.

  • dan_keil_cr Keil
    9 years ago

    As soon as the buds break, have a fungicide on! READ THE LABEL!!!!!!

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