I grew up picking blueberries in a huge area-old "orchard" gone to forest down south. None of them needed support. Thousands and thousands of bushes. Many quite large and wide, if there was enough sun to support spreading they had spread. if they were in a darker, denser part of the woods, they grew more like a tree-narrow and straight.
Possibly you have some new modern strain that likes to flop if not supported though-what are you growing?

Good question. I ordered the Northern Highbush group from Stark Bros., which would include:

Blueray
Jersey
Bluecrop

sdrone:

I don't really see any cause for concern here. First, a few months is way too early to assess the growth habit of your blueberries. Second, bushes that grow wider seem to be more productive than those that grow straight up, so you might call the wide growth a plus.

Northern highbush blueberries are normally slow-growing plants that take years to achieve their full size. I have some 15-year bushes out there that are now 5 feet tall, and the only time I have used support is when they are so full of blueberries that the canes dip down to the ground.

Don Yellman, Great Falls, VA

That makes sense to me. thanks!