Tree

Trees are structures of wood and leaf blocks, created when a map chunk is generated or grown from a planted sapling. They are found in most biomes, and abound in forest-related biomes.

Structure
Their natural height varies widely, from a minimum of 5 blocks (4 wood and 1 leaf) up to 30 blocks in Jungle biomes.

The tree canopy is composed of leaf blocks, and grows 1—3 blocks higher than the highest wood block. The canopy may begin as low as 1 block from the ground (for a tree with a 4-block trunk) up to 6 blocks from the ground (for the tallest trees). Tree canopies appear to be generated from roughly spherical clusters of leaves about 5—7 blocks across, centered on sections of trunk or branches. Leaves must be supported by adjacent trunk or leaf blocks, or will wither and disappear.

Any normal tree with a trunk height of at least 4 has a chance to grow branches (wood blocks connected horizontally, vertically or diagonally to the trunk or other branches). Most of the time, a single tree will have between one and six branches, and each branch will have between one and six wood blocks. But in reality, no limit has been found, and the largest reported tree was large enough to provide 55 wood. But this is very unlikely to happen naturally since most branches are about 3 blocks long. Branches support a much larger canopy than a tree with a single trunk. Birch and Pine trees cannot grow branches. Very rarely, "bush trees" or oak trees with leaves covering the entire trunk can be found (first found in late Alpha).

Growth and characteristics
Trees are grown from saplings, which have a 1/16 chance of dropping from leaf blocks when they are destroyed or decay. Some players harvest wood from high-efficiency tree farms. As of release 1.2 saplings now occur in four separate varieties: oak, birch, spruce, and jungle.

The sapling must be planted on a dirt or grass block, and must have a light level of at least 8 in the sapling block. A sapling will uproot with light level 7 or less in the sapling block itself unless it has an unobscured zenith (except by glass or other fully transparent materials). The sapling must also have at least 4 blocks of space above it; see the individual sections below for space requirements, as they vary between the different types of trees. If there is a ceiling above a sapling, this will limit the maximum height of the tree that can grow from that sapling.

All trees in the active chunk radius around the player make attempts to grow at random intervals. For any given tree this can work out to about 3 attempts per minute, but a tree will usually not grow until nearly 30 minutes have elapsed since planting. When the tree attempts to grow it first checks that it has enough light, then chooses which type of tree to spawn. For oak trees, it will choose either small or large; for spruce trees, it will choose either short, tall, or very tall. Birch trees only have one type.

Now that the tree has passed a light check and chosen a size to attempt, it checks if there is space to grow into what it has already (randomly) chosen to become. If it encounters an obstruction during this check, it fails to grow and must wait for the next pass before it can attempt to grow again. This means that a tree in an open field with enough light will grow quite quickly (usually right around the 30 minute mark), but a tree in a tree farm that stunts its size may make several attempts before finally growing.

''If you are standing on a sapling when it turns into a tree you will be trapped inside and begin to suffocate. You can escape by digging.''

Bone Meal forces the tree to grow if right clicked as long as all of the normal checks are in place (i.e. light, space, dirt, etc.). It does not guarantee a tree will grow, but forces it to attempt to grow. The tree must pass all normal checks, including available light level and space for its randomly chosen type, before it grows. This is important to remember when limiting tree height, as the tree may attempt to grow a tall variant and fail even when all other requirements are met.

All saplings will grow normally in The Nether and in The End, although they must be planted in dirt transported from the normal world. Leaf blocks in the Nether have the same colour as if they were placed in a drier biome.

Oak trees
Oak trees are unique in several ways compared to birch, spruce, and jungle trees. Oak trees have a much smaller space requirement, and while birch, spruce, and jungle trees can only grow through other leaves of their type, oak trees will grow into any other leaf block.

They come in two variants with wildly different properties:
 * Small oak trees are the most commonly encountered, and resemble birch trees in their shape and size. They require no horizontal clearance at the base, 1 block around the main trunk, 2 blocks from the top of the trunk up to the ceiling and 6-8 blocks of vertical clearance. Thus, a small oak tree can grow in a 1 deep hole, but not a 2 deep hole.


 * Large oak trees are more uncommon, and have a distinct look and different growth requirements. They often have "branches", outgrowths of wood on the sides of the trunk, or even freestanding and surrounded by leaves. They require 4-14 blocks of open space directly above the sapling to grow (Air or Leaves only) but can otherwise be completely enclosed on all sides (which allows for the phenomenon of 'Tree Tubes').

A large tree form exists with a single leaf block layer above the minimal 4-block trunk, allowing a tree to rarely grow in a vertical space with a height of only 5, but otherwise the maximum trunk height is 2 less than the vertical space, making the practical minimum height 6.

Leaves of small trees (but not large ones) will destroy fences, glass, paintings, stairs, pistons, torches, and doors due to a mismatch between the tree's actual and test forms. While tree trunks will not grow through solid blocks, the branches of large trees may grow through (replace) any blocks that are not directly above the trunk, including chests.

In swamp biomes, naturally occuring oak trees tend to grow in the water, and may have vines hanging down. If a sapling grows in a swamp biome, however, it won't include vines, and there is no way to grow a tree under water, giving players no way to naturally grow "swamp trees". Since they are composed of existing tree components, however, one can simply grow a normal tree and add the vines manually, and submerge them after the fact. Jungle trees, on the other hand, have vines both if they're naturally occuring, and if they're grown using four saplings (see below).

Birch trees
Birch trees, the least common type of tree, look fairly similar to oak trees in terms of height, and with leaves of a paler color, however they stand out with their unique, white bark.

There is only a single type of birch tree; they never grow branches, always having only a straight trunk. Birch trees always have leaves at least 2 blocks above the ground, whereas oak trees may be as low as 1 (at least when in forest biomes).

Birch trees require a 5*6 (radius*height) volume of free space, starting at one meter above the base of the sapling, that is completely empty of anything but leaves of any type. Birch trees will not grow if this space is obstructed by other blocks (including torches). This behavior is different from oak trees, which will grow regardless of obstructions (usually not growing into the obstructed area). Spruce trees behave similarly (see below).

Birch trees may grow faster than oak trees. A Birch tree has been seen growing from sapling to fully grown tree in under 1 day. It looks like they skip the 30 minute delay entirely; in very rare cases they even grow within one minute. This has been reported for SSP and SMP.

Spruce trees
Spruce trees, also known as pine trees, conifer trees, redwoods or sequoias, have growth patterns and requirements very similar to birch trees, though they look very different. They are most commonly found in the Taiga biome, but can be found elsewhere. Spruce wood has the same texture as oak wood, but it is a darker shade of brown, while its leaves are denser, with a darker and more blue-ish tone to them.

There are two different 'species' of spruce trees that may grow from any spruce sapling: a tall thin variant with leaves at the very top, and a shorter variant with height similar to oak trees. These are sometimes separately called sequoias and pines, respectively. Additionally, there is a third "tall sequoia" variant, with a height limit of 17 rather than 14. The leaves of the short variant tend to grow in discrete rows rather than the more "spherical" arrangement of oaks and birch trees, while the tall variants tend to have very few leaves, concentrated at the top.

Like birch trees, they do not grow branches, and have a larger space requirement than oaks. This minimum space requirement is one block taller than the birch, at 5*7 blocks, and as with birch trees, they will not grow if any block (other than existing spruce leaves) occupies this volume.

Jungle trees
Jungle trees are exclusive to the Jungle Biome and have a unique growth system. Jungle tree leaves drop jungle tree saplings. They have a unique look, unlike any of the other saplings. When planted in grass or dirt they grow in to a jungle tree with a 1x1 trunk, unlike the occasional jungle trees with a 2x2 trunk that you find naturally in the jungle biome. However, when a jungle sapling is joined by three other saplings (of any type) and it is checked for growth by a block tick or bonemeal use, it may grow into a giant 2x2 tree as are found in the jungle biome. For growth to succeed, there may be no blocks adjacent (even diagonally) to the north-western sapling (which is considered the center of the tree) up to the final height of the tree, as well as no blocks 1 block away except at the same level of the sapling. Some materials (including wood, leaves, dirt and saplings, but not vines or tall grass) do not block the growth of jungle trees. Light level and which sapling the bonemeal is used on are irrelevant.

A bug exists in 1.2.3 that transforms saplings in a 2x2 square with jungle saplings into other jungle saplings if the growth of a giant tree fails. This will not be revealed until the block graphics are updated, such as when a block is placed or destroyed nearby. This bug can be exploited to rapidly create jungle saplings from other saplings using bonemeal.

Uses
Tree harvesting is an essential first step for any player in Survival mode. The wooden blocks can be harvested for wood, without requiring tools (although an axe quickens harvesting). Each wood block can be crafted into wooden planks and sticks, which are used for crafting tools.

Wood can also be smelted into charcoal, an equivalent of coal.

When leaves are harvested, or decay naturally, there is a chance they will drop a sapling, which can be planted to grow a new tree. Decaying oak tree leaves also have a 1/200 chance of dropping a Red Apple. Destroying leaves does not require a tool; however, a sword destroys leaves negligibly faster, but this quickly degrades the sword. Using a hoe to destroy a leaf block will not degrade its durability, but does not destroy faster than your hands. Since Beta 1.7, Shears have been added to harvest leaf blocks quickly, and will drop a usable leaf block for the player to pick up.

History
Trees were introduced in Minecraft Classic and had only a single foliage color. Tree growth was added to Alpha in 0.0.14a and Creative in 0.28_01.

Birch and pine trees were introduced in Beta 1.2. Trees predating this update would appear to have multiple types of leaves, as the data indicating tree type was previously used for decay calculations.

In Beta 1.5, birch and pine saplings became available. Post-Beta 1.5 oak-type saplings will not stack with pre-Beta 1.5 saplings.

In Beta 1.8, the Swampland biome was added, with a new tree design (made of the same blocks as oak trees), which are of more uniform size and have vines growing on them. There is no way to grow these trees; oak saplings will grow normal oak trees.

In the fourth pre-release of update 1.9 (and possibly earlier) trees can sometimes be found growing on blocks of sand. This has been observed in swamp biomes.

In release 1.1, oak leaves were given a 1/200 chance of dropping a Red Apple when they are destroyed or decay.

In release 1.2, the Jungle tree became available.

Trivia

 * Trees will only grow if they are planted on a chunk of the map that is loaded into memory. If you plant saplings and then explore another more distant area of your world for a few Minecraft days, they will still be saplings when you return.
 * Before beta, trees could destroy glass if their growth would occupy the same space.
 * It seems with the addition of different types of lakes above ground, you may have floating trees. This happens since the tree is spawned when the chunk loads first. Then, the lake is spawned afterward. This leaves the tree floating above the lake.
 * If a sapling is surrounded by a 2 block tall tube it guarantees that it will, eventually, grow into a big tree. The tube forces the small tree growth to always fail each attempt. However, this takes far longer to produce a mature tree, due to the low chance that a sapling will try to grow into a big tree.
 * An already spawned tree will not grow further wood or leaves.
 * Tree glitch can be used to find mine shafts, strongholds and caves. Dig 1 block deep into the ground, plant a sapling in the hole and use bone meal while standing 1 block next to it.  Occasionally you will be inside the leaves of the tree and be able to see through the ground.
 * Two regular saplings planted near each other have a chance to grow above their normal height limit of 14. (Example: 16 tall with 57 wood)
 * A tree standing over a lava pool may burst into flames, starting a fire that will destroy the tree.
 * Trees can naturally spawn on stone, sand, and clay. It is unknown if this is a bug.
 * Trees can easily be planted on other trees by simply using 1 dirt block, however, these trees take longer to grow and they will grow into small trees unless you use tree tubing.
 * If you sprint on leaf blocks, the particles that come off them will be gray.

A Tip on Cutting Trees

 * When trying to cut a big tree (like the ones in the Taiga Biome), the best technique is to get up to the top and cut the wood from there going down (the same applies to tall trees).
 * To easily cut down a Jungle Tree, climb its vines and reach the top. From there, you should be able to cut the rest of the tree down using the above method.
 * Another easy way to cut down Jungle trees is to carve a spiral staircase as you go, leaving select blocks to stand on. Once you reach the top, simply cut those blocks on your way down. (Be on the look out for branches and offshoots).