Today is the twelfth day of the waxing moon (Shukla Paksha Dwadashi) of the month of Kartika. According to the Skanda Purana, the wedding of Tulsi with the Shaligram (sacred stone, symbolising Lord Vishnu) is celebrated today. The holy basil or tulsi is a symbol of purity and by wearing a garland of fresh tulsi leaves the Lord affirms that he will bless such devotees who are pure in their heart, in their word and deed and keep them close to him. Puja to Vishnu is considered incomplete without an offering of tulsi leaves. Tulsi vivah takes place on the next day of Karthik Ekadashi in all Vaishnavite temples. The festival also marks the end of Chaturya masa and the beginning of the marriage season.
Tulsi in Sanskrit means “unmatched” or “incomparable”. There are so many legends associated with the birth of Tulsi. During the Samudra Manthan or the churning of the Ocean, Dhanvantri, the divine Physician appeared from the ocean with Amrit or nectar in his hands. Dhanvantri shed tears of joy and when the first drop of his tear fell in the Amrita, it formed the Tulsi. It is believed that Tulsi emerged during Samudra Manthan. Another Puranic reference is that Goddess Mahalakshmi pleased with the devotion of King Dharmadhwaja and Queen Madhavi was born to them as their daughter and she was named Tulsi. When it was time for her to depart from the world, she left a part of herself as the holy plant.
The plant has medicinal properties too. Hindus revere the plant and have it in their homes as it wards of negativity and ensures positive vibrations always.