Introduce sapling check to prevent saplings from being planted in areas they wont grow in

[LeveledChemist]

Saplings will drop and immediately plant themselves next to other saplings planted by this mod, introduce a check to check for planted saplings and either don't plant them, or simply plant only one sapling if fallen from a tree.

[StimzRx]

Confirming this needs to be done. Ill add it to my to-do list. This one should be simple, so ill try to get to it in the next few days if possible.