There are some popular stories associated with Durva Grass and Bhagwan Vishnu in Hinduism. One such story connects the origin of the Durga grass with the Kurma Avatar of Vishnu Bhagavan.
During the famous incident of the churning of ocean or samudra manthan in the Puranas, Mountain Manthara was used as the churning rod and it was supported at the base by the Kurma Avatar (tortoise incarnation) of Bhagavan Vishnu. The churning resulted in the rubbing off of a few hairs from Kurma avatar. The rubbed hairs were cast ashore by the waves and on land they took the form of Durva grass.
It also believed that Durva grass appeared when amrut or elixir of life fell from the pot of Mohini avatar of Vishnu on earth. Yet another legend has it that Durva grass appeared when the perspiration of Bhagavan Vishnu fell on earth.
Durva grass, known as Bermuda grass in English, doob or Harialil in Hindi, and arugam pullu in Tamil, is held highly auspicious by Hindus. It is offered without inner shoot to Mahadev Shiva and with shoot of Vishnu Bhagavan. It is the most important offering to Ganesha.
Durva is a symbol of long life and immortality in Hinduism especially due to the highly resilient nature of the grass.
Hindus believe that Brahma resides in the root of the grass, Vishnu in the middle and Shiva in the tip. For this reason growing Durva grass helps in sin redemption.