Is it permissible to use a poisonous herbicide to clear harmful weeds from the graveyard?

If the grass is fresh, it is not permissible to uproot it, because it glorifies God, and the deceased benefits from its glorification. It is disliked to cut fresh wood and grass from the graveyard. However, if it is dry, there is no harm in uprooting it, provided that it does not harm the deceased.