Lifespan of a Bonsai Tree

Bonsai is an art form which deals with the growth and care of miniature trees.  Practically any tree can be made into a Bonsai.  The lifespan of a Bonsai Tree is the same as that of the tree in the wild.  With proper care and nutrition, many trees last generations and are passed over as prized heirlooms within families.

There are specimens which are said to be 500 years old. In the wild, the roots of the trees can grow underground in search of water and nutrients.  At home, in a Bonsai tray, the plant is entirely dependent on the owner for its nutrients and water.  Thus, the Bonsai should be cared for like a pet.  Trees which are taken care of are healthy and live longer.  They can resist pests and diseases better.  Temperature and Humidity are important parameters to be maintained.

Bonsai should not be exposed to frost or excessive cold.

Trimming of the Bonsai
Trimming plays a role in longevity by removing diseased or unhealthy branches of the tree.  If a portion of the tree has been attacked by disease or a pest, it is better to remove the branch. 
The age of a tree cannot be determined from its appearance.  This is because many trees are deliberately manipulated by twisting and pruning to give an aged appearance. 

Calculating the Age of the Bonsai
The Age of a Bonsai can be calculated by counting the tree rings in its trunk.  It may not be possible to see the rings in the trunk.  You can count the rings in any of the primary branches to get an idea of the age.