Why Tulasi is not used for Ganesh Chaturthi celebrations?

Tulasi is the daughter of Yamadharmaraja (God of Righteousness). In her youthful days, she was a great devotee of Narayana (Lord Vishnu). Once she was walking along the banks of Ganges. She came across beautiful Ganesha sitting in deep meditation to Lord Krishna. Being son of Ma Parvati, Ganesha was very handsome. Moreover any person in deep meditation state looks more handsome. So you can visualize the beauty of Lord Ganesha in that meditative state. Like Tulasi Ma, Ganesha was also in his prime and of marriageable age plus both were devoted to forms of Lord Vishnu. So Tulasi ma immediately fell in love with Lord Ganesha, she asked Ganesha to marry her.

At that time Lord Ganesha was a bachelor (Brahamchari) which is natural for any meditator. Because in meditation one has to be aloof and meditator tries to explore oneself rather than going in a relationship. So Lord Ganesha was not looking for marrying anyone. Moreover he only wanted to marry someone who possess the same divine qualities like her Mother Parvati. So Ganesha politely refused Tulasi Ma for marriage. This broke her heart. Tulasi took this as an insult and she became very angry. In her anger, Tulasi Ma cursed Ganesha that one day he will get married against his wish of not getting married.

Lord Ganesha also in turn cursed Tulasi that she will be married to an Asura (Demon) and then under a blessings from the Sages (or Gods) will become a plant. Listening this curse, Tulasi Ma realized her mistake and she begged Ganesha for forgiveness and prayed to him with divine hymns. Listening her sincere prayers Ganesha became pleased and he said "You will be regarded as supreme among the plants. All Gods will be happy with your fragrance. Lord vishnu will be specially glad to receive the worship with your leaves. But you will always be unacceptable by me in worship”. Saying this, lord ganesha left the place. Later on, as per the curse Tulasi Ma married the demon king called ‘Shankhachuda’ (or with Jalandhara). She was a very devoted wife and they lived happily for a number of years. Then one day her husband was killed in a battle with Lord Shiva.

Vishnu appeared in his true form and urged Tulasi to abandon her earthly body and return to his celestial abode. In her anger and grief, she cursed Vishnu to be turned into stone. Vishnu turned into a stone and reside on riverbank Gandaki River. People and devotees call the stone as Shaaligrama. Tulasi Ma's mortal remains decayed and became the Gandaki River, while in her next birth, she was born as sacred Tulasi plant. The Gandaki River, also known as the Narayani and the Gandak, is one of the major rivers in Nepal and a left bank tributary of the River Ganga in India. Look at our traditional science how it describes the origin of Tulasi plant both spiritually and scientifically.