The Prophet putting a palm leave on the graves

Q 3: Ibn `Abbas narrated: The Prophet (peace be upon him) once passed by two graves and said: “These two persons are being tortured not for a major sin (to avoid). One of them never saved himself from being soiled with his urine, while the other used to go about with calumnies (to make enmity between friends).” The Prophet (peace be upon him) then took a green leaf of a date-palm tree, split it into two (pieces) and fixed one on each grave. They said, “O Allah’s Messenger (peace be upon him)! Why have you done so?” He replied: “I hope that their punishment might be lessened till these (the pieces of the leaf) become dry.” Collected by Al-Bukhari. Is it permissible for us to follow the example of the Prophet (peace be upon him) in putting other similar green plants on the grave or planting an ever green tree over it for the purpose mentioned in the Hadith? (Part No. 3; Page No. 453

A: Placing a green leaf of a date-palm tree over the two graves hoping that Allah will lighten the punishment of the occupants of these graves is an individual incident confined to the Prophet alone. This was not a regular practice of the Prophet, but was only done twice or thrice according to the number of incidents. The Prophet's Sahabah (Companions), being the earnest of men to follow the Prophet's line of conduct and to benefit their fellow Muslims, are not known to have performed this practice. An exception to this is the report narrated from Buraydah Al-Aslamy who asked for two palm leaves to be placed in his grave after his death. No one among the Sahabah is known to have approved of Buraydah's line of conduct.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and companions!