Of course, your post begs the question, "If you knew about the pH, then
why didn't you prepare your planting site?

A couple of reasons. One, I'm a procrastinator. I hadn't even
really decided exactly where I wanted the blueberry plants - I just knew
I wanted to try growing some again.

Second, the place I ordered them from said they stopped doing Spring
shipping in late April, then resumed in Fall. Since it was past the
middle of May, I figured they would send me the plants in the fall, and
I had plenty of time to decide where they would go.

Instead, the plants arrived on a busy day, and just before my wife
and I planned to leave for 3 days. I was able to dig the holes, place
some dehydrated plastic in, and then top dress with composted cow
manure. Now I've finally found a local place with aluminum sulfate.
Long term, I'll also apply some peat moss and elemental sulfur.