Question
I live in Southern Alabama and I noticed some of my Crepe Myrtle have black leaves...the whole branch is black...it did flower just fine...but I guess in the last month this tree got some kind of mildew...not all my crepe Myrtle have this....what is a good spray...thank you for your help

Answer
Check and see if the leaves are sticky or where the black is sticky. IF is it this is honeydew from aphids. Aphids are small insect that suck the plant juices from the plant and secrete a substance called honeydew which is high in sugar content and sticky. A black sooty mold will grow on this honeydew. Control the aphids and the sooty mold will stop growing. Treat the tree with an insecticide called Bayer Advanced Tree and Shrub Insect Control. It is applied to the soil around the tree and the roots will transport the insecticide to the leaves and twigs and when the insects suck the plant juices they are killed. The treatment will last the full season. Here is a web link to more information on this product. Check with your local nursery fro this.
http://www.bayeradvanced.com/product/Tree-Shrub-Insect-Control/concentrate.html