Certified GKH Gardening Expert
Many extension services do feel it is effective. Here is the recipe: Mix 6 ounces of castor oil and 2 tbsp of dish soap in one gallon of water. This becomes the concentrate. Mix one ounce of concentrate per gallon of water and apply to the lawn. Reapply of it rains.
goodquuenbess was told in eastern coastal NC that an empty pepsi or other beverage boltle planted in the yard up to the rim of the bottle and the wind would cause the bottle to make the annoying sounds the moles cannot stand. they will leave the annoying area asap