From Nookipedia, the Animal Crossing wiki
Bamboo is a type of flora that debuted in Animal Crossing: New Leaf. In this game, after T.I.Y. expands into T&T Emporium, Leif will begin to sell Bamboo Shoots for 3,600 Bells. Similar to Saplings, Bamboo Shoots must be planted into the ground using a shovel, and they need one square of space around them so they can fully grow. After becoming fully grown in three days, bamboo trees will begin to spawn Bamboo Shoots underground, which can be dug up using s shovel. If not dug up in one day, Bamboo Shoots will sprout on their own, growing into more bamboo trees if they have the space to do so.
In Animal Crossing: New Horizons, bamboo trees can be found only on a specific Mystery Island. The player can gather Bamboo Pieces and Young Spring Bamboo by using an axe. Bamboo Shoots are only produced once per set of stalks. Items in the Bamboo Theme can be crafted using Bamboo Pieces, Young Spring Bamboo, and Bamboo Shoots.
Bamboo Shoots can also be obtained through favors from villagers, or after purchasing Turnips from Daisy Mae in New Horizons. They may also be eaten or given to Shrunk (only in New Leaf).
Bamboo Shoot inventory icon in New Horizons
Bamboo Tree inventory icon in New Horizons
Bamboo Piece storage icon in New Horizons
Bamboo Piece inventory icon in New Horizons
Young Spring Bamboo storage icon in New Horizons
Young Spring Bamboo inventory icon in New Horizons