Grasshoppers are devastating to gardens and crops when found in large numbers, and even small numbers of grasshoppers can destroy home gardens. You can control grasshopper populations with homemade tonics that kill the bugs and let your garden grow in peace. Make your own grasshopper insecticide so you know exactly what went into the tonic, with no questions about harmful side effects.
Mix 4 ounces of blackstrap molasses with 1 quart of water in a spray bottle and shake well. Spray directly on grasshoppers to clog their pores and suffocate them to death.
Process 3 ounces of garlic to a pulp in a food processor or spice grinder and mix with 1 ounce of mineral oil in a glass jar. Let steep for 24 hours.
Strain the garlic and oil mixture into a clean glass jar and discard the garlic pulp.
Mix 1 teaspoon of fish emulsion and 1 tablespoon of castile soap with 16 ounces of water and slowly pour the mixture into the garlic-infused oil.
Mix 2 tablespoons of the garlic oil and fish emulsion mixture with 1 pint of water in a sprayer and spray grasshoppers directly to kill them. The garlic oil mixture keeps for several months in a glass jar with a well-sealed lid.