What is the ruling and legitimacy of cleaning graves of weeds, plants, and trees?

The jurists are in agreement regarding the sanctity of the deceased Muslim, and that the site where he is buried becomes an endowment for him. Therefore, it is not permissible to exhume him or walk over his grave as long as any part of him remains. Cleaning graves of trees and plants is permissible, especially if it provides a benefit, and there is nothing that prohibits or requires it.