Tulsi Vivah is considered the beginning of the wedding season in India in the month of Kartik, which occurs in October/November every year. Tulsi vivah is conducted on the day after Kartik Ekadashi (the eleventh bright day of the new moon, Amavasya) extending upto the full moon of the month (Kartik Poornima). According to Hindu mythology, Tulsi is ceremonially married to Lord Vishnu or his avatar Krishna on this day.
According to Hindu mythology, the Tulsi plant was a woman named Vrinda (Brinda), a synonym of Tulsi. She was married to the demon-king Jalandhar. Due to her devotion to Vishnu, her husband became invincible. Even god Shiva, the destroyer in the Hindu Trinity could not defeat Jalandhar. So Shiva requested Vishnu – the preserver in the Trinity – to find a solution. Vishnu disguised himself as Jalandhar and violated Vrinda. Her chastity destroyed, Jalandhar was killed by Shiva. Vrinda cursed Vishnu to become black in colour and he would be separated from his wife. Thus, he was transformed into the black Shaligram stone and in his Rama avatar, his wife Sita was kidnapped by a demon-king and thus separated from him. Vrinda then burnt herself on her husband’s funeral pyre or immolated herself due to the shame. The gods or Vishnu transferred her soul to a plant, henceforth which was called as Tulsi. As per a blessing by Vishnu to marry Vrinda in her next birth, Vishnu in form of Shaligram – married Tulsi. To commemorate this event, the ceremony of Tulsi Vivah is performed.
Another legend says that Tulsi came out of the ocean during Amrita manthan as a younger sister of Lakshmi. She was devoted to Lord Vishnu and wanted to marry him but Lakshmi, who was already married to him, did not like the idea and cursed her to become a plant. Thus the tulsi plant was born. But the all merciful Lord Vishnu took pity and fulfilling her wish declared that when he will be in the form of a saligram she will remain close to him in the form of a tulsi leaf.
The marriage of Tulsi with Vishnu/Krishna resembles the traditional Hindu wedding. This ceremony is conducted at homes and also at temples. A fast is observed on the Tulsi Vivah day till evening when the ceremony begins.
The bride Tulsi is clothed with a sari and ornaments including earrings and necklaces. A human paper face with a bindi and nose-ring – may be attached to Tulsi. The groom is a brass image or picture of Vishnu or Krishna or sometimes Balarama or more frequently the Shaligram stone – the symbol of Vishnu. The image is clothed in a dhoti. Both Vishnu and Tulsi are bathed and decorated with flowers and garlands before the wedding. The couple is linked with a cotton thread in the ceremony.
The expenses of the wedding are usually borne by a daughter-less couple, who act as the parents of Tulsi in the ritual wedding. The giving away of the daughter Tulsi (kanyadaan) to Krishna is considered as a very good deed to the couple. The bridal offerings to Tulsi are given to a Brahmin priest or female ascetics after the ceremony.