Since pneumaticcraft hasn't been updated to 1.9+ I am not able to carry on with my pneumaticcompressing addon, one of the most popular items this added is 'compressed bone meal'. It works the same as regular bone meal however it is more efficient as you are guaranteed for a tree to grow with two uses. To craft it, use 2 regular bone meal anywhere in the crafting grid to receive two compressed bone meal. Great for skyblock maps. (3 compressed bone meal may be required for bigger trees such as spruce saplings, this is still more efficient than vanilla).
Use it in any modpack / server you want.
Check it out here: