Tulsi marriage is celebrated on the Ekadashi (11th Day) of the Shukla Paksha( Phase of the period from New Moon to the Full Moon) falling under the Kartik month(8th Month of the Hindu Calender).It is celebrated on the day of Devaatthaan (God's advent)Ekadashi. This day, after solemnising the marriage ceremony between Tulsi and Shaligram Stone (a black oval shaped stone, representing Lord Vishnu), the righteous people reap the benefits of the stature of Kanyadaan (giving the daughter's hand in marriage).
According to the Shrimad Bhagwad Purana, in ancient times, Vrinda was the wife of a demon named Jalandhar. She cursed Lord Vishnu, that he will get transformed into a stone as he had destroyed her chastity / marital honour. After which Lord Vishnu incarnated in the form of Shaligram Stone, and he told Vrinda that it is the result of your chastity, that you will stay with me as Tulsi. Whoever will get me married to you, they will go to the ultimate heavenly abode, after death. Since then, Lord Shaligram and Tulsi's marriage began to be considered symbolic of the marriage of Lord Vishnu and Goddess Mother Lakshmi.
How to solemnise tulsi marriage-
TulsiJi is called Vishnu Priya (dearest of Lord Vishnu). According to ancient beliefs, one must solemnise Tulsi marriage once in his life. And on this day, all the sins committed, get undone by observing a fast. Some ritualistic procedures have also been advised to solemnise Tulsi marriage. According to it, firstly, the pot containing the Tulsi plant, should be nicely decorated by painting with ocher (a red colour Mud paste, obtained from the Soil), limestone, and golden colour. Then, with the use of saree and other clothes, a beautiful marriage pavilion is made. Then in the evening, all the members of the house should get involved in this wedding by wearing new or clean clothes. A metal idol of Lord Vishnu or Shaligram is installed in the pavilion made for marriage. After this, the idol of Lord Vishnu should be draped in a yellow cloth. And Tulsiji should be draped in a red sari or red head scarf. First of all, Lord Ganesha should be worshipped. Shaligramji should be installed next to Tulsiji and joyous music should be played. After this, all the rituals mentioned to be performed in marriage should be followed. For Tulsiji, all the accessories of the make-up and ornamentation are to be prepared. After this, offerings of food to be made to both of them. After this, the person solemnising the Tulsi marriage, should also make a commitment to perform Kanyadaan (giving the daughter's hand in marriage). Then, after singing the hyms of both of them, people should also listen to the story of Mother Tulsi. On the next morning, again the hyms of Shaligram and Tulsiji are sung. And women sing melodious songs. After this, Shaligramji is requested that Oh Dear God please take your wife, Tulsiji to Baikunth abode (Paradise, which is Lord Vishnu's home). And Tulsiji is bid farewell.
Types and benefits of tulsi-
tulsi is an Ayurvedic plant. Its roots, seeds and branches along with its leaves are also used in making a variety of medicines Tulsi is of three main varieties - Krishna Tulsi, White Tulsi and Ram Tulsi. Each of these three have their own merits. Tulsi has many miraculous benefits too.
Regular consumption of tulsi seeds and leaf gives strength to the hair. And the hair continue to remain black and dense.
Consumption of Tulsi results in a Glowing Skin.
tulsi should also be eaten to cure leprosy.
Consumption of tulsi also gives beneficial results to the people suffering from Heart diseases.
Tulsi is also consumed to improve eyesight.
If anybody has a problem of kidney stone, then consumption of Tulsi makes sure that it does not aggravate.
Tulsi is also used in making medicines for the treatment of Tuberculosis (TB), Asthma, Cough and Cold.