I did not invent this, but someone e-mailed this to me in answer to my request for a recipe for a non-toxic insecticide to spray on herbs intended for human consumption.

Supposedly it works against just about all insect and spider-mite plant pests. And (except for the diswashing detergent in the recipe) the recipe is safe enough you could use it as salad dressing!

I was quite impressed how well it worked against spider mites and white flies that were infesting my Salvia and kratom plants.

Equipment required:

• a blender
• a fine mesh collander
• a coffee filter
• a plant sprayer
• jars to store the liquid you will make
• measuring spoons

Ingredients:

• 1 quart (or liter) water
• 1 teaspoon vinegar, it can be white vinegar or cider vinegar etc.
• 1 tablespoon hot red pepper flakes or cayenne powder
• 2 medium or 1 large clove garlic. Use strong ordinary garlic, not Elephant
• 1 teaspoon dishwashing detergent, e.g. ‘Dawn®’

Preparation:

1. Add all ingredients EXCEPT the detergent to the blender. Run the blender at the ‘liquify’ setting until everything is well blended.
2. Pour the liquid into jars and put the screw top lids on the jars. Allow filled jars to sit at room temperature overnight (for at least 6 hours).
3. Strain through the wire mesh strainer
4. Filter through the coffee filter
5. Now add the teaspoon of dishwashing detergent and mix well
6. Pour into sprayer and spray both the tops and undersides of your plant’s leaves. The entire leaf surface should be wetted by the spray.

I have found this is very effective, much more effective than Neem oil. Spray every several days until no pests are visible, then spray once or twice a week for several weeks thereafter. If pests return resume spraying.

The only drawback is if you will be quidding the leaves you might find your mouth is burning from the red pepper. It would make sense to gently wash the leaves before drying them for smoking, or if you will be quidding them. Washing would remove the detergent and most of the capsaicin (the ingredient that makes red pepper hot). You certainly don’t want to inhale red pepper fumes!

I found this recipe worked very well, it was much more effective than Safer Soap, or Neem oil.

But if you found the recipe as given above was ineffective for your plant’s particular pests you might want to ‘tweak’ the recipe by adding Neem oil, or by using chamomile tea in place of water. Neem, and chamomile (supposedly), are insecticidal. Or you might even experiment with adding oregano or sage or thyme to see if these herbs increased the insecticidal effect. Or add cinnamon (cinnamaldehyde is an insecticide).

I’m not sure whether the vinegar is actually doing anything, 1 tsp. vinegar per quart of water is a VERY dilute acetic acid solution. Perhaps it is included in the recipe to neutralize the alkalinity of the detergent.

© 2007 Walt