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Florida Gardening

Black 'stuff' on my Crape Myrtles

15 years ago

What the heck is wrong with my myrtles? They look deathly ill. They have a black covering of their leaves and some of the stems. Must be some type of mildew, fungus or something similiar. Most importantly, will it kill them and what do I need to do?

Thanks,

Ron

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Comments (4)

manature
15 years ago
I am pretty sure Tom MacCubbin had a recent article about this and said it is pretty much harmless. I believe it is the residue from some sort of bug and it is more a cosmetic problem in the normal run of things. I think he offered a suggestion to clean it off (maybe just water spray?) but indicated it really wasn't necessary. I got the impression it will go away by itself.

Hopefully someone else read the same article and retained more of the details than I did! (I'm OOOOLD. Ya gotta give me a break!)

Marcia
drewsmaga
15 years ago
You probably have sooty mold. If you google it, you can learn more about it than you'd ever want to know! Bottom line: you can wash it off with a strong blast of H2O, soap spray works better. Find out what insect is causing it & eradicate it. It won't kill the Crape unless it gets soooo overwhelming that it doesn't allow the leaves to photosynthesize (that would be a rare circumstance.) My gardenias are alwayd getting it. . . . Looks ugly, but is generally not lethal.
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It's 'black sooty mold' caused by mold growing on the 'honey dew' secreted by aphids. Spraying with insecticidal soap is recommended. The white spots are most likely powdery mildew which some varieties of crape myrtles are subject to mostly in the spring, especially if there is not good air circulation and they are not in full sun. Sometimes trimming out some of the interior foliage will help, plus you can spray them with an anti fungal solution. Good luck. Crape myrtles are beautiful trees and are mostly carefree. Incidentally I find using the Gilmour 362 professional hose end sprayer to be the most convenient way to spray. Amazon.com carries it. Here is a link that might be useful: Google search results for sooty mold on crape myrtles ...
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manature
15 years ago
Yeah, that sounds about like what Tom MacCubbin said. Thanks, drewsmaga! Good info for me to have, too, since I inherited two pretty pink crapes when I moved here.

Marcia
cycadjungle
15 years ago
Yes, you just about have to have sooty mold. It is a mold that grows on the excretions from insects. Any time you see that on any bushes, you should look closer because you have some sort of insect problem. It can be scales, but in this case, it is probably aphids. It is common for large plants even in the wholesale nurseries to get black because of this mold, but it usually happens in another month or two. As others have said, it doesn't kill the plant but it looks ugly. I would spray the plants with something like Malathion, or any other general purpose insecticide to get rid of the aphids. If we had lots of rain, the mold would then wash off in a few weeks. An old remedy is to mix about 4 tablespoons of baking soda per gallon of water, and that is supposed to take out the mold in less than a week.

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