Honeydew and Sooty Mold

 

Honeydew (sticky leaves) and sooty mold (black leaves) are the by-products of aphid, scale, leafhopper or whitefly activity. All the above parasites are often tended by ants which gather the honeydew and also protect the pests from their natural enemies. So, the first order of business, if possible, is to deprive the ants of their access to the tree. Once there are no ants, the natural predators and parasites of the above pests will be able to keep the aphids, scale and whiteflies under control. If your tree(s) is free-standing, i.e., not touching a fence or other plants, ant access can be denied by applying a three- to four-inch band of “Tangle foot” to the tree trunk. By the way, the tree(s) should also be pruned so no limbs or foliage touch the ground. If the above procedure cannot be followed, you may spray your tree. One spray is often enough to suppress the pest problem for several months. If not, a second application two to three weeks after the first spray should be adequate to suppress the problem.