Geranium and Petunia Budworms
I have tried everything to get rid of the Budworms that destroy my Geraniums and Petunias. Any new ideas? I have used Imidicloprid soil drench and Spinosad but still our plants are devastated by early August.
Tobacco budworms definitely can do quite a bit of damage to petunias! Unfortunately, budworms are resistant to most insecticides and so may not affected affected by the treatments that you made.
If it is a small planting, then hand removal may be helpful. The caterpillars are active around dusk (use a flashlight and pick & destroy them). If that's not a possibility, then try using a pesticide with Bt (Bt stands for Bacillus thuringiensis and is a bacteria based product.) The caterpillars will need to eat the pesticide for it to affect them so make sure to get it on early so that the small caterpillars are exposed. Keep in mind that Bt can affect many other caterpillar species (including those that turn into desirable butterflies or moths) might be feeding in your garden. So like any pesticide, use it carefully and with a targeted approach.
For much more information on budworms, check out this Colorado State University Extension article: http://extension.colostate.edu/topic-areas/insects/tobacco-geranium-budworm-5-581/
Thanks for using Ask an Expert and good luck!