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Citrus Problems

So I have a lemon tree and a dwarf orange tree that are both having problems. I'm not really sure what to do about them.

The orange tree has a powdery black mold that is growing on the leaves and there was only like 3 oranges on it this year.


The lemon tree is kind of a joke. I get around 10 off of it a year, but it has a weird looking thing on some of the leaves. A lot of the leaves are also yellow.


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I can't enlarge your pics to see any detail, so I'll just make a wild guess. The black stuff sounds like sooty mold. It grows on "honeydew," which is excreted by insects such as aphids and scale. Carefully check your trees for both of those insects, as they are common pests of citrus. Also look for ants, because ants have been known to "farm" aphids in order to obtain honeydew from them. The ants will carry the aphids to different parts of the plant. If you remove the aphids, the ants will bring more to replace them.

Insects like scale and aphids suck the sap from plants, so they could be the cause of the yellowing leaves, as well.

I cannot see the "weird thing on the leaves" to which you refer. Any chance you might be able to post a larger image?
Last edited by Kisal on Mon Mar 22, 2010 12:48 am, edited 1 time in total.

Cool Member
Posts: 77
Joined: Fri Apr 03, 2009 11:46 am
Location: Santa Maria, CA

ah, well I'm not sure why I my pictures wont enlarge... But there is a ton of ants on both the trees. What should I do to get rid of the ants?

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Try typing ant control into the Search the Forum feature. You will find a bunch of stuff written here already about it.

Here's one thread to start you off:


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Just a suggestion Dub. The leaves look as if there could be some form of Leaf Miner Damage.
This can be caused by several pests that burrow under the leaves surface feeding on the cells that devide the leaf.
Where the cells have been eaten there appears a silvery trail below the leaf surface.
Most are relatively harmless unless there is a severs infestation.

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