If you plant bells, there is a chance it will grow bells on the tree or it will be a regular tree.
The bigger amount of bells you bury, the better the chance it will grow into a money tree.
Trees (not matter what kind) will not grow if it falls under certain conditions such as being right next to buildings, PWPs, etc...; if there are too many trees in one area, or if one tree is grown surrounded by other saplings.
I said that if you bury bells, it can grow into a money tree or a regular tree. And if the conditions are right to grow a tree (not beside buildings, PWPs, or not surrounded by other saplings) then yes it will grow every time.