Huh....who knew!?! Baking soda neutralizes the ph in the soil and nothing will grow there. Use baking soda in a 6" wide area around all of the edges of my flower beds to keep the grass and weeds from growing into my beds. Just sprinkle it onto the soil so that it covers it lightly. Do this twice a year - spring and fall.
Lay down a thick layer of CARDBOARD in your raised garden beds to kill the grass. It is perfectly safe to use and will fully decompose, but not before killing any grass below it. They’ll also provide compost and food for worms.