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.
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.
Bury a banana peel 1" down at the base of a rosebush. The potassium will feed the plant and help it fight of diseases. ***Used banana peels, egg shells, coffee grounds & crushed Tums with calcium when planting tomatoes!