Pine trees are a decorative item. They do not generate naturally, but must be grown. They are found in the Organic section of inventory, where they look like, well, pine trees. Pine trees are one block wide and two blocks tall, and have no collision.
How to Obtain
You can obtain pine trees either by growing them yourself or by trading for them. A pine tree grows from compost placed in an arctic world. Not every compost will automatically grow a pine tree. Compost must have unobstructed sky above, so that snowfall can reach it. Pine trees go through three stages of growth. If a pine tree is mined before its final stage of growth, it will drop flax. Once mined, pine trees can be traded.
Pine trees can be used decoratively in and of themselves, or they can be crafted into Festive Pine Trees. To place a pine tree, put it either on a block of compost or on a flower pot. If you place a pine tree without compost or a flower pot, it will soon die and turn into flax.
If you want to place a pine tree without compost or a flower pot, place it first on compost. Then shovel the compost and quickly switch to your pick and mine the compost while it is still in its crumbly shoveled state.
Pine trees were introduced in late 2013 as part of the holiday update.
On Macs, selecting a pine tree to place it will show a light green transparency of a sapling rather than the full-grown pine tree. However, the tree will appear full-grown when actually placed.