Making bonsai with herbs is not uncommon. The Art of Bonsai is nothing but mimicking a tree in small form. Though it is immensely popular in Japan, our ancestors knew how to grow a plant in a small plant.
Thousand years ago, the Hindu Vaidya used this method to conserve herbs found in deep forest that were of great medicinal value. Those physicians grew herbs in the pots and used it for healing. Though the plants could not grow their original size, they thrived in the regulated atmosphere where they were taken care of.