Problem: Sooty Mold (Jasmine)
This common black mold is found on a wide variety of plants in the garden. It is caused by any of several species of fungi that grow on the sugary material left on plants by aphids, mealybugs, scales, whiteflies, and other insects that suck sap from the plant. The insects cannot fully digest all the sugar in the sap, and they excrete the excess in a fluid called honeydew, which drops onto the leaves below. The sooty mold fungus develops on the honeydew, causing the jasmine leaves to appear black and dirty. Sooty mold is unsightly but is fairly harmless because it does not attack the leaf directly. Extremely heavy infestations prevent light from reaching the leaf, so the leaf produces fewer nutrients and may turn yellow. The presence of sooty mold indicates that the jasmine or another plant near it is infested with insects.
Rain will eventually wash off sooty mold. Plants can also be rinsed off with a solution of soapy water, using a mild soap. If only a few leaves are infested, just wipe off the mold with a wet rag. Prevent more sooty mold from growing by controlling the insect that is producing the honeydew. Inspect the leaves and stems of the ivy and nearby plants for insects.