Tulsi Puja Diwas, also known as the Tulsi Vivah, is a significant Hindu festival that celebrates the marriage of the sacred Tulsi plant to Lord Vishnu. It is observed on the 11th day of the bright fortnight in the Hindu month of Kartik. Devotees believe that performing rituals and ceremonies on this day brings prosperity and happiness to their homes.

The Tulsi plant is considered holy in Hinduism and is worshipped for its medicinal and spiritual properties. It is believed that Tulsi is an incarnation of Goddess Lakshmi and worshipping her on Tulsi Puja Diwas brings blessings and good fortune. The plant is also known to have various health benefits and is used in Ayurvedic medicine for its healing properties.

On Tulsi Puja Diwas, devotees decorate and worship the Tulsi plant with flowers, incense, and lamps. They offer prayers and perform a ceremonial wedding of Tulsi to Lord Vishnu. The festival is celebrated with great devotion and fervor in India, with devotees observing fasts and attending special ceremonies at temples dedicated to Tulsi.