alh,
The best I can recommend is to get some peat moss and Pine bark mulch and replant them in that.It still can be in the ground,with about 60% Pine mulch and 40% peat.
What's the pH of your irrigation water? Brady

dig 1 up and plant in a big pot with mostly peat moss and see if it'll improve?

Don't use Black Cow on blueberry plants use Black Hen Lowes has Black Hen. there black Hen out line on bag.
A cow is almost all calcium milk, big bones, horns, hoofs and hair, feed on grass that load with calcium A chicken feed on grain and has small bones.
In Fla. its very hot and sandy this makes fine pine bark more suitable to hold moisture than mosses the northern folks can use moss without any problem 80 some 90 degree few hours in day.

Dig all of them up, knock most of the soil off them. Dig a hole 15 inches deep, 30 inches in diameter. Fill with three quarter peat miss and one quarter potting soil. If you have pine fines then use the mix recommended by Brady. Put the plants back in and water as usual. My guess is it will take one year to get their feet under them and then next year they will take off.

RM

OK-- peat moss and pine mulch it is-- I will do as you all say.

Thank you!