Praise be to Allah.
With regard to reciting Quran when visiting the grave, this is something which has no basis in the Sunnah.
It is not prescribed in Islam, and the fact that it is not prescribed is supported by the hadeeth of the Prophet (peace and blessings of Allah be upon him): “Do not make your houses into graveyards, for the Shaytaan flees from a house in which Soorat al-Baqarah is recited.” This was narrated by Muslim and al-Tirmidhi from the hadeeth of Abu Hurayrah. This indicates that graves are not the place for reading Quran, hence the Prophet (peace and blessings of Allah be upon him) encouraged reading Quran in our houses and told us not to make them like graveyards where it is not read. Another hadeeth indicates that they (graveyards) are not the place for prayer (salaah) either. The Prophet (peace and blessings of Allah be upon him) said: “Pray in your houses and do not make them like graves.” This was narrated by Muslim and others from Ibn ‘Umar. A similar report was narrated by al-Bukhari, who included it in a chapter entitled Baab Karaahat al-Salaah fi’l-Maqaabir (Chapter on it being disliked to pray in graveyards); thus he indicated that the hadeeth of Ibn ‘Umar could be understood to mean that it is makrooh to pray in graveyards. Similarly the hadeeth of Abu Hurayrah may be understood to mean that it is makrooh to read Quran in graveyards. There is no difference between praying and reading Quran in this regard. Abu Dawood said in his Masaa’il (p. 158): “I heard Ahmad being asked about reading Quran at the graveside. He said, ‘No [that should not be done].’”
It is not prescribed in Islam to put “aas” leaves (a kind of tree) or fragrant herbs or roses on the grave, because this is not what the salaf did, and if it was good, they would have done it before us. Ibn ‘Umar (may Allah be pleased with them both) said: “Every bid’ah (innovation) is a going astray, even if the people think it is good.” (Narrated by Ibn Battah in al-Ibaanah ‘an Usool al-Diyaanah, 2/112; al-Laakaa’i in al-Sunnah, 1/21, a mawqoof report with a saheeh isnaad).
We ask Allah to bestow mercy upon the deceased Muslims. May Allah bless our Prophet Muhammad.