Question about scale on Meyer lemon

Discussion in 'Citrus' started by Alicat, Jun 7, 2007.

  1. Alicat

    Alicat Member

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    I have a small Meyer lemon tree. When I bought it 7 years ago it was not a healthy looking tree but it had a couple of lemons on it, which I found enchanting, so I bought it anyway. It has never had many branches or leaves, and what leaves it has had it has frequently lost. It has also been severely affected by scale. I've read through all the posts on this forum, plus a bunch of other material, and I feel armed to try to solve some of my Meyer's health issues, but I'm still perplexed about the scale.

    My tree lives indoors in a south-facing window from mid-October until mid-May and then outside the rest of the year. It seems to often get scale and needs to be treated for it several times a year. I'm always very thorough about cleaning the trunk, branches and leaves -- one by one -- plus I spray too, but the scale never goes once and for all. I can't understand it. Is the scale a cause of the tree's ill-health, or is the ill-health a cause of the scale? And why does it persist despite all my TLC?

    Thanks for your input,
    A
     
  2. Millet

    Millet Well-Known Member 10 Years

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    Alicat, actually citrus scale is quite easy to eradicate. The reason that your problem keeps returning is probably due to attempting control of the pest, branch by branch, and leaf by leaf, therefore not eliminating 100 percent of the insects. The recomended method of scale control in the citrus industry, is spraying the tree with a horticultural oil. Purchase a quart of UltraFine Horticultural Oil, at any Home Depot, or at most larger nurseries. Spray the entire tree with a solution of 1 percent UltraFine and 99 percent water (see the label). As this is an oil /water combination be sure to shake the solution frequently. Spray all branches and both sides of the leaves. Spray in the late afternoon after the temperatures have cooled. UltraFine Horticulture Oil is completely non-toxic and entirely safe to use. Just do not spray the tree in the heat of the day. Besides scale, UltraFine controls most all other pest that attack citrus. - Millet
     
  3. Alicat

    Alicat Member

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    Thank you Millet, I will try that.
     
  4. wildredbear

    wildredbear Member

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    I had the same problem with a small potted key lime tree that I grow for the leaves; the leaves are used in making a Thai soup I enjoy. The scale kept coming back because the local ants were farming the scale colonies.

    To address the problem without purchasing oil, I power sprayed the scale off the tree with a water hose and common spraygun hose attachment. I also prevented the ants from accessing the tree in two ways: I keep a water tray filled under the tree which it greedily drinks during hot weather, and also kept other plants from touching the tree to prevent the ants from finding a bridge onto the tree. It took a couple of weeks using the high pressure spray to power spray the scale away until they stopped returning. I also picked off any scale that I missed between power spraying. I guess there were eggs or some missed scale the first few times.

    After they were completely gone, the scale did not return. For two years now, I have had no problems with scale. I still go out of my way to keep other plants from touching my fruit trees because the ants are quick to access the trees if I give them any chance. They have several unpleasant things they try to farm on my citrus, but using water to power spray them off works very well. I learned this trick from the LA Arboredum. They use this cheap and chem-free method to protect citrus and roses.

    If you try it for roses, be sure to allow for them to sun dry. Roses will mildew if they don't have enough sun after spraying to completely dry.

    Good luck. Hope this helps.

    PS. I had the same problem with my dwarf improved meyer lemon last year, but followed the steps above and no more scale.
     
  5. Millet

    Millet Well-Known Member 10 Years

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    I glad to hear of your success. I might mention that scale do not crawl across the floor and then up your tree. Scale is mostly an air born insect, distributed by the wind or by contact from plants, people or animals. The water pan under your tree should give added humidity to the tree but it unfortunately does not have any effect on scale. - Millet
     

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