How do I "Spawn" Beehives in Minecraft?

Solution 1:

A 5% Chance. However, for that chance to start happening, you'd need to make sure that a flower is no more than two blocks away from your oak/birch saplings, and that the flower and sapling are on the same elevation.

As quoted by the MineCraft Gamepedia;

"5% Oak or birch trees grown from saplings that are within 2 blocks of any flower on the same y-level have 5% chance to grow with a bee nest containing 1–3 bees."