Tulsi Pooja / Tulsi Vivah is the ceremonial marriage of the Tulsi (holy basil) plant to Lord Vishnu in his form as Shaligram or to his avatar, Sri Krishna. The Tulsi wedding signifies the end of the monsoon and the beginning of the wedding season. The festival is observed between Prabodhini Ekadashi and Kartik Poornima and this year will be observed on Devotthana Dwadashi falling on 1st November 2017. It is believed that the Tulsi plant was a pious woman named Vrinda / Brinda, whose husband was the Asura King Jalandhar, who due to her piety and devotion to Vishnu, became invincible. Even Shiva could not defeat Jalandhar, so he requested Vishnu, who disguised himself as Jalandhar and tricked Vrinda. Her chastity destroyed, Jalandhar lost his power and was killed by Shiva. Vrinda cursed Vishnu to become black in colour and to be separated from his wife, Lakshmi. Vrinda then drowned herself in the ocean, and the gods transferred her soul to a plant, which was henceforth called Tulsi. Lord Vishnu granted her a boon, that​ he would marry her in her next birth, Therefore, Lord Vishnu, in form of Shaligram, married Tulsi on Prabodhini Ekadashi. Vrinda’s curse was later fulfilled when Lord Vishnu was transformed into the black Shaligram stone and in his Rama avatar, was separated from his wife Sita