There’s an interesting story about why Tulasi is closely associated with Lord Vishnu.
According to Hindu puranas, Shankachuda was a celestial demon who terrorized gods. He could not be defeated by the combined strength of all gods, because the source of his strength was believed to be his chaste and devout wife Tulasi.
To weaken the demon’s strength, Lord Vishnu takes the form of Shankachuda and approaches Tulasi. Unaware of the trick, Tulasi welcomes the disguised Vishnu, unknowingly committing a sin. Upon realizing the trick played on her, Tulasi curses Vishnu to turn into a black stone.
Moved by the unwavering devotion of Tulasi to her husband, Lord Vishnu blesses her with a permanent place near him. This is why the Tulasi plant is closely associated with Lord Vishnu. When devotees offer a garland made of Tulasi leaves, it serves as a reminder of the strength of faith and the bond between the divine and the devoted.
