Can I use white vinegar diluted with rain water as a source of watering and...
Can I use white vinegar diluted with rain water as a source of watering and soil acidification for potted and raised bed growing of BB in will county Il?
Will County Illinois
You can give this a try, but you must try it carefully! You won't be able to acidify a non-acid potting medium this way, but using water with an acid (in this case vinegar) added to lower the water's pH can help maintain an already-acid soil. To do this, you must measure the pH of the acidified water, which should be adjusted to about 5.0 -- the pH at which the soil should already be for blueberries. Too much vinegar won't make the soil become more acid, but it will hurt your blueberries. Though acidified irrigation is used by commercial growers, it's not generally recommended for home use.
Here's an overview of soil pH and some of the issues with trying to change it, from the University of Colorado extension:
I did find a Q&A from the New Mexico State extension that describes growing potted blueberries with acid irrigation:
It's far more important to pot up the blueberries in an acid medium to start, use acidifying dressings and mulches (blueberries have shallow roots, don't "dig in" additions), and use fertilizers formulated for acid-loving plants. If they're already potted in a mix that wasn't designed to be acidic, re-pot them properly.