According to Judith R. Baskin (Cambridge Dictionary of Judaism and Jewish Culture, 2011, pp. 134-135),
"The biblical law of "uncircumcised" fruit (orlah) prohibits consuming fruit picked from a tree in the Land of Israel within three years of its planting (Lev 19:23). According to rabbinic interpretation of "fourth-year planting" (neta revai) ...may only be eaten in Jerusalem unless it is redeemed."
According to the Mishna (Kidushin ch.1, #9), these laws are not actually restricted to the land of Israel, but must be observed worldwide because they are halacha l'Moshe mi-Sinai.
So how do we know that fruit that is sold in stores in America, etc., follows these laws? If not, why are we allowed to eat it?