Have you got the golden shovel? Well, if not here's how to get it (you'll need it to make money trees.)
Buy another shovel so you can bury the one you already have. Leave it for 24 hours and then dig it up again (it'll be gold). With golden shovels, you can bury money and it'll turn into a tree. But it might not grow into a money tree. If you bury 1,000 bells, there's a 1 percent chance of it growing into a money tree. So if you bury 100,000 bells, it'll definitley grow into a money tree. But the thing is, money trees are for display only. As you've probably noticed with fruit trees, is that they grow back within a few days. But with money trees, they don't grow back. When you shake it, the money won't grow back. This works for both games, I think.