Depending upon which one of the bittersweet vines (there are three different vines called Bittersweet), lowering the pH of the soil might help.

The native, non-invasive, and endangered American/False Bittersweet vines likes acid soils around 5 just as blueberry bushes prefer.

The non-native, invasive, and most common Asian Bittersweet Vine perfers soil ph about 6.

I'm not sure about the other less common Nightshade Bittersweet.

You've probably got the Asian Bittersweet Vine or a hybrid of it and the American. Lowering the soil pH won't kill it, but it will help control it, while you manage to eradicate it completely. The best way to kill it is to cut it off at the ground and paint the top of the stub with RoundUp. I normally hate RoundUp, but with some weeds there is hardly any other way. If you try to spray the vines with RoundUP, you will kill your blueberries, but you can cut the vines, and paint the stubs without getting it on the blueberries.

Every one of the Bittersweet berries will produce more vines, so getting the soil pH down to 5 will help your blueberries and slow the vines down.

Good Luck, maybe someday it and kudzu's ranges will overlap, and they will wipe one-another out.

Greg

Here is a link that might be useful: Asian Bittersweet vine

Thanks Greg.

I was figuring it was going to be rip and tear and then paint on roundup on everything the broken bits. A forrester who surveyed my land said it is asian bittersweet...