Q. What bracha do you make on cranberries and strawberries? What happens if you made the wrong brocho?

A. Shulchan Aruch (O.H. 203: 2) rules that one recites hoadama on berries grown on bushes that yearly loose their trunk and only the roots remain next year. Therefore on strawberries the correct brocho is hoadama and so rule many Poskim (See Mishna Berura ibid.3, Igrois Moishe 1: 86, Maharsham 1: 196, Vesein Bracha p. 392-394, Shaarei Bracha P. 707 n.758 et. al.)
If the plant grows within 3 tefachim (9 inches) of the ground, such as cranberries, we treat them as bushes and thus we recite on them hoadama. (Vesein Bracha p. 392-394, Shaarei Bracha P. 437 n.758 et. al.) The Halachos of Brochos quotes the p’sak of Horav Shlomo Zalman Auerbach, z’tl, “Cranberries grow on creeping vines which grow along the ground. Although the plant produces fruit year after year, nevertheless, since cranberries grow within nine inches of the ground, its brocho is hoadamah.”
However, the Laws of Brachos by Rabbi Binyomin Forst, writes that the brocho on cranberries is haeitz. In Halacha, when the proper brocho is hoadama, the recitation of haeitz would be incorrect, and would result in a bracha levatala and in effect no first bracha having been recited on the food at all. If one recited haeitz, some Poskim maintain that he should take a small bite and then out of doubt, make hoadama on a vegetable or similar. (Vesein Bracha p. 392-394, Shaarei Brocho 17 3 n. 4).
Horav Shlomo Miller’s Shlit’a opinion is that, the correct brocho on both strawberries and cranberries is hoadama. However, on strawberries even bedieved, after the fact, the haeitz recited on them is levatala (on vain), and a new hoadama blessing should be recited. For cranberries, after the fact, one should follow the last above mentioned opinion.

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