Yellowing Azaleas

Discussion in 'Landscape Architecture and Design' started by machine, May 29, 2001.

  1. machine

    machine LawnSite Member
    from OH
    Messages: 101

    I am wondering what is causing some Azaleas to turn a bit yellow but the others are looking fine. What can I do to turn them back to green?
  2. Evan528

    Evan528 LawnSite Silver Member
    Messages: 2,144

    lower the PH. Use a fertilizer called holly tone.
  3. greens1

    greens1 LawnSite Senior Member
    Messages: 352

    Before you apply anything make certain you know what the problem is. It could be ph, it could also be mites, borers or disease. Yellowing is generally the first sign that the plant is, for some reason, not reciveing the neutrition that it needs to stay healthy.

    The first thing you want to do is run a ph test. If the ph is high, above 6.2 or so, then you will need to apply chealated Iron. Follow the directions for the iron application.

    Lowering soil Ph is, in most cases, a gradual process often taking several years. This is usually done by applying aluminum sulfide fertilzer over a period of years, but will probably not help your Azaleas in the short term.

    Jim L
  4. gusbuster

    gusbuster LawnSite Bronze Member
    Messages: 1,932

    The first thing I would do is check watering first, then the ph level. Could be the first sign of improper watering. Though, by experience, I would say it is a soil\fungus\iron\insect problem.
  5. CMerLand

    CMerLand LawnSite Senior Member
    Messages: 393

    The first thing I would do is look to see if the azaleas are in full sun, then I would turn over the leaves of the plant to see if there are alot of little black spots. If there is then you can probably see the lacebug that are causeing the problem, particularly this time of year on azealeas in full sun.

    Lacebug feeds on the underside of the leaf. The black "honeydew" is what they excrete after feeding. High populations of lacebug will prevent the plant from producing chloryfil turning the leaves yellow. Treat with a systemic insecticide as control with a contact is difficult as they are under the leaves.

    Once damaged these leaves will remain stipled until they drop off as part of the growing plant.

    Let us know what it turns out to be.

  6. Avery

    Avery LawnSite Bronze Member
    Messages: 1,389

    If your problem is not insect/disease problems a quick shot of Ferromec should green them right up.

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