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jbaldwin_gw

Hollyhock rust and weevils

jbaldwin
9 years ago

My hollyhocks are suffering from two problems, which I have been treating separately, but they still aren't looking better.

1. Hollyhock rust: the leaves have the classic pustules on the bottom of the leaves. First only one plant was affected. I took off the bad leaves, and sprayed with neem oil. Soon more leaves became infected and so I cut the plant down. Now a couple more plants are showing signs, so I again took off the affected leaves and this time sprayed with copper. The plants are spaced quite a ways apart, we don't have a lot of rainfall, and I water with a soaker hose. These plants are 3 years old and this is the first year I've had rust. I have a huge row of them and I don't want to lose every plant. I read about cornmeal and milk treatments, but not really sure how to apply them or if they'd be effective at this point. One other change this year is I put compost down and weed blocking fabric and grass mulch on top. I'm not sure if that could contribute to rust. There seems to be some debate on poor vs rich soil causing rust.

2. weevils: this is the second year for these frisky buggers. Last year I tried to control them with D.E. and neem oil. This year the leaf damage seems more extensive. I am doing the same treatment. Last year I was worried I might lose all of them, I found weevils in many of the seed pods. However, the plants came back and were big and healthy until the weevil population exploded again and now I have rust spreading.

Any help would be appreciated. I usually like organic solutions, but at this point, I do anything to save my plants. I can post pictures if that'd help.

Comments (11)

  • charleney
    9 years ago

    I sprayed mine with BAYER DISEASE CONTROL. That killed the rust 100%. Best foliage I have ever had. I have no idea about weevils. I have read that BT would kill them, but I really don't know. I only spray for fungus, so have been lucky to not have any more problems.

  • schoolhouse_gw
    9 years ago

    charleney, did you spray after rust appeared or before? That's critical I think. However, as it's been said on this forum before "If you love hollyhocks, you expect the rust".

  • docmom_gw
    9 years ago

    I'm growing hollyhocks for the first time and expect my first blooms any day. I thought they were biennials, meaning they would sprout one year, bloom the second summer, and then die. Are they actually perennial, so might bloom for many years? Or do you simply have new plants growing every year so your patch blooms yearly?

    Martha

  • schoolhouse_gw
    9 years ago

    They are labeled biennial and most are, but I know that I've had some hollyhocks plants that come back every year from the same root. In fact small foliage at the base of the spent plant stays nearly green all winter(!).

  • jbaldwin
    Original Author
    9 years ago

    Well thanks everyone for the reply. Charleney- I'm looking into Bayer disease control. Then I saw the Bayer 3 in 1 control and I thought that would be great for the rust and the weevils. But I'm a little concerned about the Bee Decolonization effect. So I'm still deciding on that.
    Docmom- my hollyhohcks are perennials. I started all of them from seed. The first year, the plant and foliage grows. Then it dies back in the fall and I cut everything down. The second year it blooms. I cut the stalks and they rebloom at least one more time, just fewer blooms on each rebloom. And then each year they keep coming back. That's why I love them. A lot of bang for your buck once they're established. And, this is my very first year with rust, so usually that's not a problem for me.

  • docmom_gw
    9 years ago

    Thanks, JBaldwin. I was actually planning on letting mine die off as the native perennials around them got established. Oh, well. I can probably bear to enjoy them for as long as they want to hang around. LOL.

    Martha

  • concretenprimroses
    9 years ago

    My hollyhocks were covered with rust last year. I had to cut them down and didn't get to enjoy them. I cleaned up very carefully and threw around some corn meal. Then when the plants put out new fall growth I put more cornmeal. This spring I again cleaned carefully and more corn meal.
    No rust, beautiful holly hocks, the tallest I've ever had.
    That said, the Bayer products seem to be very good. I don't know how toxic they are, but they are the only thing I know that gets rid of lily beetles so I do use it on the few lilies I kept once those darn things arrived.
    Kathy

  • nulty
    9 years ago

    Oh boy that terrible Hollyhock Rust is so unsightly,..i get it every year,..my hollyhocks are about three years old,..however i always use Neem Oil and Liquid Soap,..a teaspoon of each in a Pint of water then heavily spray the under leaf first,..then the over leaf,..i spray when ever we have a dull day,..don't spray on a sunny day as the droplets will burn the leaf,..i have to admit i fail to spray in time,..that is before there are signs of rust appearing,.. rather than when it first shows.

    I must try that Bayer Disease Control.

    Philip

  • charleney
    9 years ago

    I do not use the all in one. I mainly go roses and use that for the only spray. The HH were rusty before sprayed, and it cleared them right up. Good Luck!

  • nomore2023
    9 years ago

    As soon as I saw a little rust appearing on lower leaves of my hollyhock, I removed the really bad infected leaves. Then I used copper fungicide powder. That really seemed to help as it controlled the spread.

  • redoana
    8 months ago

    Are all of you aware of the risks to beneficial pollinators when using any pesticides in your gardens? Please be informed of the catastrophic effect pesticides have had on pollinators worldwide and the very serious consequences to our environment. Thank you!

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