Baking soda neutralizes the ph in the soil and nothing will grow there. use baking soda around all of the edges of flower beds to keep the grass and weeds from growing into beds. Just sprinkle it onto the soil so that it covers it lightly. Do this twice a year - spring and fall.
Pothole Gardening! What a fabulous idea! Walt and I once did a guerrilla cottage garden for a friend who lived in a teeny tiny cottage with a teeny tiny yard. She came home from work one day, and had no idea how her yard had suddenly turned into a blooming oasis. Great fun!