| By nature, petunias tend to be sticky. This is quite evident if you handle the plants such as when you're pinching off faded flowers. The black specks might very well be seeds; look for opened seed pods still attached to the stems of the plants. These will be either brown or tan and still attached to the stems where flowers once were. Seeds of petunias and about the size of a grain of salt and a dark brown. Another possiblity is frass (bug poop). If the leaves of your plants have holes eaten in them, the caterpillars feeding on them may have left some excrement. Inspect your plants very closely for signs of insect pests to rule out the possibility of frass. Best wishes with your garden! |
