another pinner says: baking soda neutralizes the ph in the soil and nothing will grow there. I 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. I usually have to do this twice a year - spring and fall.
Homemade Weed Killer 1 gallon of white vinegar, 1/2 cup salt, Liquid dish soap (any brand), Empty spray bottle. Put salt in the empty spray bottle and fill it the rest of the way up with white vinegar. Add a squirt of liquid dish soap. This solution works best if you use it on a hot day. Spray it on the weeds in the morning, and as it heats up it will do its work.
My friend has something very similiar to this on a large tree trunk out side her kitchen window. It really is very sweet...she actually also has a few small windows and door lamp that lights up. I just find the whole thing charming and I am sure a small child would find delightful.
Puissant et Facile à Faire : le Désherbant Maison au Vinaigre Blanc.