Where do you live?
And what is the prevailing pH of the region's soil?

Have you fertilized? Blueberries need a fair amount of nitrogen.

And what is your watering scheme/ plan/ sequence/ practice? Their roots need to remain evenly moist.

Here is a link that might be useful: your other post

Also how much sun do they get and when?
Doesn't sound like you have one particular problem. If they aren't thriving, you have to find out what makes them happy and then provide it. I think they like some shade, lots of water, and acid, humus-y soil. And in my yard, A LITTLE RELEIF FROM THE DEVIL BUNNIES!!
Sorry, I can't help myself!
:)
Good luck with the blueberries.