Question
my crepe myrtle gets blacksooty mold on the trunk and all of the leaves.  I've been told it is caused by insects which secrete a sticky substance.  The tree never blooms and looks terrible by the end of its season.  I think the ants carry the insects to the tree.  

Answer
Okey dokey, here is an answer I got to the question of the black sooty gung on the crepe myrtle.
It came from a fellow groung crew member on a site I belong to on organics.
Hope this helps.


A: The dripping is the waste or "honeydew" of small insects called aphids or plant lice. They can be temporarily eliminated with strong sprays of anything, including water. Compost tea with orange oil or other plant oil products added to the water works better of course. The strong spray rips the pests off leaving their mouth parts still stuck in the plant tissue killing most of them. But, they will come right back unless the stress in the trees that brought them on in the first place is removed. Stress in the plant can be caused by too much or too little water, too much or the wrong kind of fertilizer, soil compaction, and soil contamination caused by herbicides and other toxic chemicals. One of the most common causes of stress in trees is deep planting. Make sure the tree is not too deep.
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Sandi-Organic gardener~Tree-Hugger~Native Texan
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Hi Carolyn;
I have looked all over for an answer to this.
I have never experienced what you are describing, so I had to try to find something about it on the web, and can't.
I don't understand how ants would be carrying another insect to the trees.
Maybe if you got some Agricultural soap, and washed down the tee trunk to get the stuff off, then you could treat to repel the insects.
I have sent a couple of emails to try to get some answers from some who would know more about it, but it may be a couple of days before I egt an answer.
IF, by any chance, you use Amway products.
I can tell you that LOC would be perfectly safe to wash the tree with. Put about 1 cup per gallon of water in a garden sprayer, spray the tree, let it set 15 to 30 minutes, then wash off with water.
You could wash iut with a forceful stream out of the hose, and that would wash it all off.
Maybe it would just wash off with just oplain water in a forceful stream.
If this is caused by an insect, we need to identify that insect to be able to know what will repel it for good.
If I get answers back, I will let you know. I will post a followup.
I will continue to search for an answer.
Charlotte