Bonsai Size

Most bonsai are created from plants that otherwise would grow into towering trees or billowing shrubs. You can purchase bonsai or start your own by digging up a smallish wild tree or a seedling that popped up in your yard. This plant will need its roots pruned before it goes into a pot. The far-reaching roots of wild plants must be untangled and shortened to fit into its pot.

 

The top of a new bonsai also might need to be cut back to bring it down to bonsai size, which is usually under 4 feet. (Bonsai are classified according to form and size, and the smallest are less than 7 inches high.)
To shorten a trunk artistically, cut it back to within a few inches above its desired height. Trim the bark from the portion of trunk above the highest remaining branch, and pare the stub to a taper. Bend the next-highest branch upwards, tying it against the tapered stub, with some padding to prevent the string or wire from marring the branch.
After a few weeks, when the branch can hold the upright position without assistance, remove the ties and cut back the stub, with a sloping cut, to the base of the now-leading branch.