So I live in an 11b area of the Canary Islands.
Apples should not bear fruit because the temperature is not chill enough. However, there are plenty of apple trees everywhere, even on public spaces, all with fruit.
Given this situation, I'm considering planting 3 varieties close together to grow into a "single tree", but prior to that, I'm trying to understand why are they bearing fruit if the chilling requirements are not met?