How to plant money trees and get the most money out of them.
Find a Glowing Spot
Every day, there will be a glowing spot on the ground somewhere in your town.
Dig it Up and Bury Money
Use a shovel to dig up the glowing spot. You will get 1000 bells, and the hole in the ground will glow. Don't fill the glowing spot with dirt, or plant anything other than money in it.
You can bury any amount of money, but it's recommended to bury 10,000 bells if you have that much. The glowing spot will stay there all day, so you can take some time to earn more money first if you wish.
The tree is guaranteed to grow three bags of 10,000 bells if you bury 10,000, but any more than that is not guaranteed. It's rare for the resulting bell bags to exceed 10,000. If you bury less than that, you will get three bags of the amount that you buried.
How to Turn Your Money into Bell Bags for Burying
To get a bag of bells from your money, open your inventory and put the cursor on your money, and press A. You can choose the amount to turn into a bell bag.
Money Trees Turn Into Regular Trees
After you remove the bell bags from a money tree, the tree will not grow any more bell bags. It becomes a regular hardwood tree.