Organic Pest Control for Herb Gardens: Recipes & Companion Plants

Homemade Sprays That Work

Test all sprays on a few leaves first; wait 24 hours. Apply in early morning or evening.

Core Recipes

• Garlic–Oil–Soap: 3 oz garlic + 2 tsp mineral oil (24 hrs) → add 1 pint water + ¾ oz soap. Dilute 1:20. (Aphids, mosquitoes)
• Garlic–Onion–Cayenne: 1 bulb garlic, 1 onion, 1 tbsp cayenne, 1 qt water (24 hrs) + 1 tbsp soap. Refrigerate 1 week.
• Soap–Oil–Hot Pepper: 1 gal water, 3 tbsp soap, 3 tbsp oil, 4 tbsp hot pepper, 3 garlic cloves. Strain. Spray undersides.
• Pepper Juice Spray: 1 cup hot peppers + 2 cups water (1 day) → strain. ½ cup concentrate per gallon water.
• Rhubarb Leaf Tea: 1 lb leaves boiled 30 min in 1 qt water. Toxic—keep away from kids/pets.

Pest-Specific Tactics

• Cabbageworms: Sour milk in head center, or salt/flour dust (1:2). Saltwater soak (1 tbsp/gal) floats worms out.
• Grasshoppers: Blend 1 gal spirea leaves + 1 qt water → strain. ½ cup mix + 2 tbsp soap + 2 gal water. Spray perimeter.
• Japanese beetles: 2 garlic cloves + ½ cup dried chiles + 1 qt water (blend, strain). Spray roses weekly.
• Slugs: Beer traps (Kingsbury malt beverage most attractive). Or diatomaceous earth barrier.

Companion Plants That Repel Insects

Plant these among herbs: basil (all types), citronella grass, lemon balm, lemon thyme, lemongrass, pennyroyal, geranium (skeleton-rose), Vick's plant, Iboza vine, eucalyptus varieties.

Other Handy Formulas

• Powdery mildew: 1 tsp baking soda per quart water (3 tbsp/gal).
• Whitefly/aphid/spider mite: 1 tbsp dish soap + 1 cup veg oil → 1–2 tsp concentrate per cup water.
• Ants: Mint, tansy, cinnamon, citrus peels. Vinegar-water spray on trails.

Rotate sprays to prevent resistance. Healthy, well-pruned, properly fed herbs resist pests best.