Cunningham's Encyclopedia of Magical Herbs - Scott Cunningham 1985

Grass
The Herbs

Powers: Psychic Powers, Protection

Magical Uses: Suspend a ball of green grass in the front window of the home to drive out evil and to protect it. Tie knots in grass around the home for the same purpose.

Blades of grass, carried, help psychic powers.

Use green grass to mark a wish on a stone, or simply rub the grass against it to make a greenish spot. Visualize your need and then bury the stone or throw it into running water.