Tulsi, or holy basil plant, is considered to be the beloved of Lord Krishna. Tulsi Vivah ritual is performed during the waxing phase of moon in Kartik month starting from the Kartik Suddha Ekadasi to Kartik Purnima. While performing the Tulsi vivah ritual women listen to the Tulsi Vivah Katha. There are several versions of Tulsi Puja story this is one of them.
Once there lived an old lady who used perform the Kartik Snan and then water Tulsi plant and offer prayers. She used to worship Tulsi without fail and used to perform the Tulsi Vivah ritual. After the ritual, the old woman always ask the Tulsi plant to fulfill her wish that her dead body should be carried by Lord Krishna to the pyre.

Saddened by this fact, Tulsi began to wither and she started shedding her leaves. One day Lord Krishna visited Tulsi Devi and found her in a real bad shape and wanted to know the reason.
Then Tulsi Devi narrated the story of the old woman who daily asks for her dead body to be carried by Lord Krishna to the pyre.
Lord Krishna gave his usual smile and said that the wish of the old woman will be fulfilled and asked Tulsi Devi to forget about the problem and asked her to return to her glorious form.

Her family members and neighbors arrived on the scene and decided to move the dead body of the old woman. But the body could not be removed. It had become so heavy that even 10 people together could not move it.
Tulsi Devi then remembered Lord Krishna. She prayed to the Lord save her devotee who is lying on her feet.
A large number of people had gathered at the scene as the news of the death of old lady spread and the subsequent miracle of the body becoming so heavy.
Soon a young boy appeared and asked what all the commotion was about. An elderly person narrated what had happened.
The boy said he will move the body and went to the dead body and chanted some words into the ears of the old woman and touched the body. The body now became lighter like a flower. The boy then shouldered the body to the pyre.
People gathered there were surprised to see this miracle. The pyre was lit and the young boy slipped out of the crowd.
Only Tulsi Devi knew that the young boy was Lord Krishna who had arrived to fulfill the prayer of her devotee.