Lack of Flowers in Petunia May Be Tobacco Bud Worm

Q. My husband planted some gorgeous petunias in early April. At first they were all blooming but now there isn't a single flower in either of the planters. We noticed many holes in the leaves so my husband sprayed them with Sevin thinking that would do the trick. All we have is two planters filled with very healthy green plants but no flowers.


A. This is most likely tobacco budworm. The adult is a moth but the damage is done by the larval or caterpillar stage. In this stage the caterpillar feeds on flower buds and leaves.

            The giveaways that it is tobacco budworm are the lack of flowers, holes in the leaves from feeding, the type of plant and the time of year. The flowers fail to open so lack of flowering is a pretty good indicator the pest is present. Small holes in the leaves are another good indicator.

            Besides petunia, tobacco budworm likes geraniums and nicotiana. Once in a while we might see damage on roses.

            In the future, if you have these plants, look for holes in the leaves starting in April or May. That would be a pretty good time to start thinking about getting control because its population builds through the summer if not stopped.

            Check your plants for these caterpillars as the sun is setting. This is the easiest time to find them and pick them off of the plants with your fingers. During the daytime they like to hide out close to the soil.

            Tobacco budworm has become fairly resistant to a lot of insecticides so control is a little bit difficult. This is why you probably did not get controlled using the insecticide Sevin. Be really careful with that insecticide because it is pretty hard on bees.

            You might try an insecticide with Spinosad on the label. Dipel or Thuricide might give you some control. Otherwise use insecticides that contain synthetic pyrethroids in the list of ingredients.

            Regardless of the insecticide used, always spray either very early in the morning or at dusk when bees are no longer present.