Usually around the end of June gardeners notice that the flowers on their petunias and geraniums have just stopped blooming. Our hanging baskets are no exception, either! Not only do the flowers disappear, but there are little holes in the leaves and the developing buds as well, preventing new blossoms from even opening up at all. The culprit is a small, green and brown worm called the tobacco budworm and they love to eat petunias and geraniums. Their coloring helps camouflage them and they are quite adept at hiding along the stems of the plants. It is the larva of a moth that flies in the evening and beats its wings very rapidly like a hummingbird. Small, round, black caterpillar droppings (poop) can even be found on the leaves and stems as well as the plants becoming sticky from sap dripping from the wounds.
The most effective methods for controlling the budworms include many organic as well as synthetic insecticide options. On the organic side, we recommend Spinosad or Spinosad Soap as one of the very best options for controlling caterpillars in general, and it works on contact as well as by ingestion, stopping the caterpillars from eating within a few hours of exposure. Sevin, Hi-Yield Bug Blaster, and our latest; Cyonara, work quickly on contact, but will also provide a longer lasting control over multiple weeks. Fortunately, once the budworms are controlled, the flowers will begin to bloom again in just a week or two.