Thickening the trunk

It is better to start with a reasonably thick trunk as the tree doesn't put on much girth once its in a bonsai pot.Various ways in which the trunk can be made to thicken include:

• Allowing several seasons of growth in the ground
• Letting the roots escape out of the pot into the earth
• Growing long sacrifice branches for local thickening
• Incorporating areial roots to fuse with the trunk

Growing in the ground. The trunk must be chopped several times to encourage taper and curves.

Roots escaping through the drainage hole into the earth.This makes it easier to remove the tree when thick enough by simply cutting the escaped roots.

A sacrificial branch being used to thicken the trunk base.

Sacrificial branches can be grown at any point which needs thickening, although they are most often used for the base.The branch is allowed to shoot for a season or two and cut off when the required thickness is achieved.

Care should be taken that sacrifices do not draw away too much energy from other important points on the trunk.For instance,sacrifice branches at the very top thicken the entire tree but can severely weaken lower branches.It is advisable to cut them back if this happens and grow new sacrifices the following season.

Aerial roots being fused with the trunk to thicken the tachiagiri.