Q. I have read that the brocho on blueberries is not necessarily HaEitz and that it depends on what kind of tree or bush it grows. Could the Rav please clarify

A. The Halacha definition of a tree is a plant which survives and produces fruit one year after another. Blueberries grow on bushes which endure and continue to produce fruit year after year, therefore the blessing should be haetz, despite not actually appearing like a classical tree. Mishna Berura (203: 3) mentions that although the opinion of Mogen Avrohom and others is to recite haetz on fruits of small trees even when they are less than three tefachim high, (from 9.45 in.- 24 cm. to 12 in. – 30.48 cm.) the minhag is to recite haadama.
However, Igrois Moshe (O.H. 1: 85) maintains that the berries and fruits common in our lands usually grow on trees much higher than three tefachim and the minhag is to recite haetz on them, even when one is in doubt if they grew on bushes less that three tefachim high.
Vesen Bracha (p. 393-394), Vesoz Habracha (p. 372: n. 6), Shaarei Bracha (p.510: n. 27) and others rule to recite haetz on blueberries (or “uchmanim” as they are known in Hebrew), unless one knows for sure that they grew on plants less than three tefachim high..
Horav Shlomo Miller’s Shlit’a opinion is similar.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a