The ruling on sprinkling water on a grave and placing trees on it so that it does not erode

Question:
Among her questions—Your Eminence, the Shaykh—she asks: What is the ruling on placing trees on a grave with the intention of holding the soil together and preventing the grave from eroding due to strong winds, as well as sprinkling it with water to preserve it from erosion?

Answer:
There is no harm in sprinkling it with water and placing pebbles on it; pebbles are placed on it to hold it in place. As for trees, no, there is no need for that, because something might be believed about them. As for placing a palm branch, which the Prophet (peace and blessings be upon him) did, that was in the case of two graves where he looked upon their punishment—(peace and blessings be upon him). As for us, we do not know who is being punished and who is not, so it is not prescribed for us to place a palm branch or trees on it. However, if pebbles are placed on it and it is sprinkled with water, that is good for the purpose of securing the soil.