Crepe myrtle fungus

popeye_patAugust 6, 2009

About a month ago I noticed my tree had what looked like black soot and salt over all the leaves. I'm ashamed I let it get so far with noticing it but.... A net search identified the salt as aphids and the soot as fungus. As suggested I sprayed all the leaves (it's only 5'tall) with dish soap and cooking oil. That killed all the aphids and the fungus but now the fungus won't go away. It's dead I'm sure but short of wiping all the leaves when it's soft with morning dew is there anything else that will get this stuff off. I'm afraid it's hurting the tree. We've had lots and lots of rain and that hasn't washed the stuff off. Thanks Pat

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brandon7 TN_zone(7)

The black stuff you are seeing on your crape myrtle is black sooty mold, not fungus. It's there because of the favorable environment caused by the honeydew produced by the aphids. It's not usually a health issue for the plant, although in really severe cases it can be.

Are you worried about the health of your crape myrtle or the aesthetics? If the health of the tree is your main concern, stop worrying and the problem will correct itself. If the immediate aesthetics are important, you may have to resort to gently rubbing each leaf. If it were me, I'd just wait a few weeks.

    Bookmark   August 6, 2009 at 11:15AM
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ken_adrian Adrian MI cold Z5

where in the world did you come up with the witches brew of soap and cooking oil ... are you a witch?????

oiling leaves in the heat of summer.. can do more harm than any aphid will ever do ...

i agree ... if the aphids are gone.. the black stuff will disappear.. if you dont kill the tree first ...

when that happens.. only time will tell ... once it isnt being replaced or built up every day ... then every rain shower will reduce it ...

my only suggestion ... is that you insure that there is no scale.. because they do the same thing.. and your witches brew will have no impact on them ..

good luck...


    Bookmark   August 6, 2009 at 2:35PM
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brandon7 TN_zone(7)

I thought the same thing about the cooking oil, Ken, but when I looked on the web, I found that there were such recommendations. I just shook my head and figured what's done is done. If the tree is still alive after a few weeks, then the cooking oil curse didn't take and the tree survived. I certainly wouldn't suggest it for future treatments, but I can't send Pat back in time.

    Bookmark   August 6, 2009 at 2:44PM
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I posted a question about this and one of the members referred me to this link. This definanatly describes Sooty Mold. I looked that up on the web AND yes one of the places said to spray with dormant oil (whatever that is) and do it when the tree is dormant. So that would be cool weather???? This is the link I used

    Bookmark   August 8, 2009 at 11:49AM
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jean001(z8aPortland, OR)

It was said/asked " do it when the tree is dormant. So that would be cool weather???? "


That would be when it is dormant. as in without leaves for deciduous trees, as is a crepe myrtle.

    Bookmark   August 8, 2009 at 11:47PM
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