Orange trees may spawn in most non-arctic biomes.
As a source of oranges, an orange tree is a valued crop. Orange trees spawn spontaneously near another orange tree or from placing an orange in a block of dirt or compost. Newly spawned orange trees may not produce fruit until they've grown larger.
Oranges will spawn on leaf and leaf-covered trunk blocks year-round, with the exception of early summer. They are harvested by hand. If the block they are on despawns, they will fall to the ground. They will eventually despawn if left on the tree.
Trunk blocks will yield wood, one per block harvested or three if an axe is used. Harvesting a trunk block will despawn all blocks of that tree on the same or higher layer. Despawned trunk blocks will rarely produce wood.