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leena1947

Rust and black spot on New Dawn

leena1947
10 years ago

I have had two New Dawn climbers for about 20 years and bought a new one last spring because I love them. I had bought these roses because I had read that they are "almost disease free". Not mine! Even the new one is starting to develop rust and some black spot. They are in full sun, I water from the base, feed them, dead head them. I spray them every spring several times with a fungicide. What else can I do?

Comments (11)

  • taoseeker
    10 years ago

    Those two are the worst on the roses, and difficult to do something with. The only thing that has worked for me is stop using artificial fertilizers in the entire garden, lawn included. I use a bit of pelleted chicken fertilizer early in spring (or other organic fertilizer, I vary a bit), and a second round with a dry pelleted type fertilizer when the first flowerbuds start to show (often vegetable based, they don't smell as bad). I try to find someting with about as much potassium as nitrogen, and don't overdo the fast acting nitrogen.

    I swear by seaweed meal (!!) and compost, it strengthens the plants some how, and sometimes I use a liquid organic fertilizer when the first flowers appear. That's the time when the roses are looking for more nutrients, I always have a few plants I give a bit of extra fuzz like that.

    And most importantly, don't give up, keept at it for a few seasons. It takes time to get it right, and then the situation is more stable.

  • cecily
    10 years ago

    Hi Leena, where are you located? I'm curious because your roses have both rust and BS simultaneously. Also, are your New Dawns own root or grafted? How large are they? ND is widely available as a grafted plant so I'm wondering if you bought them at a big box store and the plant is virused. Normally, ND is a VERY healthy, large rose.

  • diane_nj 6b/7a
    10 years ago

    Also, please describe what you are calling "rust". Rust looks like the dust from Cheetoes/Jax cheese corn curls, and typically isn't found on the east coast of the US. You may be seeing some other fungal disease, or just old decrepit leaves. Let us know what fungicide you are using. thanks.

  • jacqueline9CA
    10 years ago

    Can you post a picture of what you are calling "rust" on your roses? Diane gives a good description of it above. Here is a picture of rust - it appears on the back of rose leaves:

    Jackie

  • susan4952
    10 years ago

    I am curious, too. Never had any rust in my zone 5 garden. New dawn is a big healthy monster for me. A smidge of BS in the fall.

  • leena1947
    Original Author
    10 years ago

    Thank you all for the great responses!
    Here is what I do: we only use organic fertilizer on the lawn. We make our own compost year after year, there's always one "burning". I fertilize the roses, twenty some of them, with Bayer rose granuals and occasionally with Miracle Grow for roses. I make compost tea from our "worm farm" and use it regularly on my flowers and vegetables. Jackie posted a picture of rust and that looks exactly what I have on the New Dawn except my leaves have much more of the brown spots. The other roses have never had any. I bought the roses from a very reputable nursery. We live in Washington state north of Seattle. Ten days ago I sprayed them again with Ortho's Rose Pride Funginex and so far the new growth is disease free.

  • michaelg
    10 years ago

    If you are using the Bayer 2-in-1 product with fertilizer and Di-syston (disulfoton)--it is seriously dangerous and IMO should not be allowed on the market. I speak as one who uses a synthetic pesticide routinely and is familiar with levels of hazard that various chemicals pose. Disulfoton is deadly poisonous to mammals in the amounts this product contains.

  • leena1947
    Original Author
    10 years ago

    Thank you, michaelg, for the info. I'll make sure I won't buy it anymore.
    Jacqueline3, here is a picture of the leaves on one of my older New Dawns.

  • michaelg
    10 years ago

    That's rust for sure. If the black things are like little shiny eggs, that is an alternate form of rose rust sporulating bodies, usually seen more in fall and winter.

    Pardon some of us for the skeptical questions, but some American gardeners tend to use the word "rust" to mean "some kind of foliar fungus." And rose rust is not that common away from the west coast.

    I'm no expert on rust, but I think it will stop spreading with warm summer weather, if you have that.

  • jacqueline9CA
    10 years ago

    Leena, yup, that is rust. What I would do is:

    1) Remove every single leaf which has those spots on it (they contain spores, and can spread to other roses) carefully - they make spore "dust" which floats all over the place. What I do is hold a brown paper bag under them so that they drop directly into it. Close the bag and dispose of it in the garbage, not your compost bin.

    2) Spray the bush with a fungicide only spray (not 3 in 1,2 in 1, anything that contains food, etc - just a fungicide). Of course, follow the directions.

    3) Keep watching for more rust, and repeat the above. You can and will get control of it. It can spread, as I said, to nearby roses if you don't actually remove the spore infested leaves.

    Good Luck -

    Jackie

  • leena1947
    Original Author
    10 years ago

    Thank you michaelg and Jackie. I will do what you have suggested, I already started picking the infected leaves. Thanks a million.
    Leena

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