Short answer
A fresh green branch on a grave has a basis in the sunnah, and Ibn Abidin calls it recommended, though some scholars say it was special to the Prophet ﷺ. Bought flowers and wreaths laid as a mourning custom are not from the sunnah, and Deobandi scholars advise against them. Sheets and decorations on graves are not allowed.
Ibn Abidin records that placing green branches on a grave is mustahabb, following the Prophet's ﷺ act, and that cutting fresh grass from a grave is disliked because green plants glorify Allah. Cut flowers and wreaths laid as a custom are discouraged, and sheets (chadars) on graves are not permitted.
The four schools agree on this.
Explanation
Once the Prophet ﷺ passed two graves and said that the two people in them were being punished. He took a fresh palm stalk, split it in two and planted one piece on each grave, saying: perhaps it will be lightened for them as long as these do not dry.
From this hadith, Hanafi scholars, as recorded by Ibn Abidin, say that placing a green branch on a grave is recommended, and that pulling up fresh green grass from a grave is disliked, because living plants glorify Allah. Some other scholars hold that this act was special to the Prophet ﷺ, because he was shown the state of those in the graves.
- Planting grass, small plants or a shrub on the grave, where the cemetery allows, is fine.
- Placing a fresh green branch now and then is fine.
- Watering the grave so the soil settles is fine.
- Avoid wreaths, bouquets and cut flowers laid as a mourning ritual copied from other traditions; Deobandi scholars advise against this.
- Avoid sheets (chadar), lamps, incense and decorations on graves.
- Avoid spending large sums on any of this. Charity in the person's name benefits them far more; see sadaqah for the dead.
The real gift at a grave is your dua. Greet the people of the graves and pray for them; see visiting graves and the dua for visiting the grave. For flowers at the funeral itself, see funeral flowers.
The evidence
Quran, Surah Al-Israa 17:44
تُسَبِّحُ لَهُ ٱلسَّمَٰوَٰتُ ٱلسَّبْعُ وَٱلْأَرْضُ وَمَن فِيهِنَّ ۚ وَإِن مِّن شَىْءٍ إِلَّا يُسَبِّحُ بِحَمْدِهِۦ وَلَٰكِن لَّا تَفْقَهُونَ تَسْبِيحَهُمْ ۗ إِنَّهُۥ كَانَ حَلِيمًا غَفُورًۭا ﴿٤٤﴾
The seven heavens and the earth and whatever is in them exalt Him. And there is not a thing except that it exalts [Allah] by His praise, but you do not understand their [way of] exalting. Indeed, He is ever Forbearing and Forgiving.
Living plants glorify Allah, which is the reasoning Hanafi scholars give.
Sahih al-Bukhari 1361
Sahih... لعله أن يخفف عنهما ما لم ييبسا ...
"Perhaps it will be lightened for them as long as these do not dry."
This is the basis for placing green branches on graves.
Where the ruling is recorded
- Radd al-Muhtar (Ibn Abidin), Kitab al-Salah, Bab Salat al-Janazah. Placing green branches on graves and not cutting fresh grass from them.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.