TIP: Check out the aged line of Rosemary, Santolina, and Lavenders.
In addition, you can find older plants in gardens, which could be trained as bonsai. You want to search for herbs above one year. The ideal plants to train as the bonsai are the Geraniums and rosemary family.
How to choose bonsai:
When you find a group of large, matured bonsai, you want to search through the healthy selection. The plants should have shapely and stunning posture with appealing branches. The best texture however the plants that have been trimmed frequently are. The plants trimmed often and used as store plants is easiest to grow or train as bonsai. Look for the plants with pleasant shapes.
When choosing herbs to train as bonsai make sure that, you understand the needs of the plants. Some plants will die during transplant, since it causes shock. Other plants may not suffer from transplant shock. Learn more about the plant to avoid shock. Transplant shock comes from moving the plant from field to pot, etc.