The only current purpose of Rubber Trees is for their Rubber Wood (RedPower2) which differs from "normal" Rubber Wood in that it can only be crafted into sticks (1:8 ratio) or each piece can fed through an Extractor for a 1:1 exchange for Rubber.
How to growEdit
In order to grow one of these massive trees, you must make enough room for it to grow.
To grow one you need a Rubber Sapling (RedPower2) at the center of a 3x3 square of dirt. It is adviseable to place torches close outside of this 3x3 square to allow growth to continue overnight.
You do not need a 20x20 grid of clear space around the trunk of the tree, but growing it too close to anything might impede its leaf growth at higher levels. You do need free space ABOVE the tree (at least 10 blocks, adviseable to have clear sky above it).
Note: You can NOT use bonemeal and there is no way to speed up their growth rate.
Its better that if you want to build a massive tree house that you plant more than one tree at a time.
Since Rubber Trees take real-world hours to grow, it may be beneficial to bury a Dimensional Anchor below the tree to keep the sapling loaded constantly. It is most useful to plant the sapling in the center of a chunk, then make the anchor set to keep only that one chunk loaded. When the tree does eventually grow, it will load as many chunks as it needs, then unload them because of the lack of nearby players. It is also advised to remove the anchor after the tree has grown to prevent lag build up for other players.
- You can not use Bone Meal on these trees to speed up growth.
- Player planted trees do not seem to grow as high as a naturally occuring version. You can get decent size trees it is more of a lucky dip.