Hi, I also have the same problem so do hope for some answers here. Mine are wilted and the buds just drop off. They are also turning brown. I'm near central ny.

Dahlia's have to have well drained soil and at least 6 hours of sun. We have have had pretty heavy rains here in NY. I would try to rough up the soil around the plants to help dry out the soil and pray for some sun. Remove all the brown buds and the lower leaves to get some air flow . I hope that you don't have tuber riot, keep an eye on them and if they are still wilted after a few days of sun ,you may have to do some digging and remove the mushy tuber sections, spray the good piece with lysol and replant them. Good Luck

Can Lysol or liquid Lysol?