Organic Pesticide Recipes

Roberts RanchGardening

These are recipes that have been handed down and around by master gardeners, organic farmers, and horticulturists.  They work, but you need to use them more often.  Also, it is better to spray in the evening when the sun is not hot and direct.  


Soft Soap Sprays

6 tbsp. Ivory Snow and 1 gal of water  (I’ve also used dish soap)

Best sprayed in the evenings when sun is low


Repellent sprays can be made from plants such as Tansy, Artemisia, Tomato, Garlic, Onion, Cayenne or Rhubarb.  Make a spray by boiling 2 lbs of leaves (or 20 cloves of Garlic)  in 2 qts. of water for 30 minutes, then strain and allow to cool.  This is then mixed with 1/2 once of soft soap flakes dissolved in 1 liter of hot water.  This helps the spray penetrate.  I have also used Cayenne Pepper found at the herb store, mixing it with water and soap, then straining so as not to clog the sprayer head.  Then spray.  


Insecticidal Vegtable Oil

I mix this up in large quantities in a used milk container.  Then I use it throughout the year as my concentrate.

Mix 1 Tbsp. dishwashing detergent to 1 C. vegetable oil

To spray plants, mix 1 Tbsp of stock solution to one cup of water and spray plants. Use a fine spray and apply until you have runoff.  Controls aphids, mites and some other insects.  It is not harmful to humans or animals.  Phytotoxicity may occur on certain plants such as squash and crucifers.  Spray in the evenings.  Sometimes in the really hot summer, I rinse the leaves in the morning.


Bug Juice

Collect 1/2 cup of a specific pest and mash well.  Mix with 2 cups of water and strain. Mix 1/4 cup of this bug juice and a few drops of soap with 2 cups of water, and spray. Don’t make yourself sick too!  Use nonfood utensils and wear plastic gloves.


Garlic Oil

Finely chop 10-15 garlic cloves and soak in 1 point of mineral oil for 24 hours. Strain and spray as is, or dilute with water and add a few drops of soap add tobacco juic to strengthen the mix.


Hot-pepper spray

Blend 1/2 cup of hot peppers with 2 cups of water.  Strain and spray.  Caution: Hot peppers burn skin and eyes.


Other pesticides

Insecticidal oils are made from petroleum and plant oils.  Dormant oils are petroleum based and control overwintering stages of mites, scales, aphids, and other insects.  The oils can damage certain plants such as Japanese Maple and will also remove the blue bloom form blue spruce.

Summer oils are lighter petroleum oils are used in summer and will not burn plants as badly.  They  will control aphids, spider mites, scales, psylla, mealybugs, and some caterpillars.  Oils may cause leaf damage.  Spray test areas, wait a couple of days to see that plants are unharmed.


Diamtomacious Earth (DE)

A nontoxic mineral product, mined from fossilized shell remains of an algae know as diatoms.  This fine powder has microscopic, sharp edges that peirce soft-bodied insects and cause them to dehydrate.  I spread this on the soil before planting marigolds or impatiens; otherwise, by the time I notice there is damage (which usually occurs at night)  the plant has been stripped of all its leaves.  There are many insects controlled by this product including cutworms, thrips, and slugs.


Neem oil

Is extracted from the Neem tree native to India.  It is a broadspectrum insect poison, repellent, and feeding deterrent.  It also stops or disrupts insect growth and sterilizes some species.



Pyrethrins are derived from the flowers of pyrethrum daisies (Chrysanthemum cinerariifolium and C. Coccineum) The dried flowers are finely ground to make an insecticidal dust.  Pyrethrins are extracted from the dust and used in sprayable solutions.  Pyrethrins attack an insect’s central nervous system, providing the rapid knockdown that gives many gardenenrs a satisfying feeling of revenge.  At low doses, however, insects may detoxify the chemical and recover.