Three Simple Organic Pesticides for a Healthy Garden

by mbryce2012 on May 20, 2013

Insects can ravage a healthy garden in no time, which is why both amateur and master gardeners alike rely on organic pesticides to keep their fruits, vegetables, herbs and flowers free of both bugs and chemicals.

Ranging from sprays that simply deter pests, to dusts that kill them, organic pesticides are derived from various oils, plants, seeds, and even the sharp ground exoskeletons of ocean crustaceans.

In this article, I’ll give you three basic methods to keep your garden organic, healthy, and clear of destructive insects.  All of these methods are low in cost, completely natural, and easily obtainable either from your local garden center, online, or by using ingredients found in your kitchen or from your garden itself!


Diatomaceous Earth

Made from the finely ground fossils of tiny sea creatures called diatoms, diatomaceous earth is an abrasive powder that cuts open the insect’s hard outer shell as it crawls across the sharp sand-like particles.  Within forty-eight hours, the insect will wither up and die.

organic pesticides diatomaceous earth

Diatomaceous Earth is a white powder that kills insects after they crawl across its sharp edges.

Application is simple:

  1. Water plants well, making sure to apply a fine mist to the leaves or area where infestation is occurring.
  2. Lightly dust the plants with the diatomaceous earth.
  3. If aphids are a problem, you may have to use a special duster to spray up underneath the leaves where aphids usually hide out.
  4. Wait a few days, and most of the pests should be gone.

The benefits of using diatomaceous earth are many:  It’s organic, simple to apply, and insects cannot build immunity to it because it works mechanically.  It effects all crawling insects, unlike some treatments which only target specific varieties.  It’s inexpensive, and it will never go bad in your garage or garden shed (it doesn’t expire).

The downside is that rain or watering will wash the white powder right off, and then you’ll have to reapply.  Also, your vegetable garden will turn a ghostly white!

While the diatomaceous earth is non-toxic, you’ll want to keep it away from your eyes, nose, and mouth.  If you get it in an eye, it will sting and irritate, so you’ll need to wash it out right away.  It’s probably safest to wear protective goggles and a paper mouth cover (or bandana) while applying.

Cayenne and Citrus Oil for Ants

ant organic pesticides

Photo courtesy of Jens Buurgaard Nielson on Wikimedia Commons.

If it’s ants you’re trying to get rid of, try this very simple mix.  In a spray bottle, shake up one cup of water with one tablespoon ground cayenne pepper and ten drops of pure citrus oil (plain lemon or orange oil works as well).  Spray on areas that are infested with ants.  Just be aware of sunlight when you use this treatment, as too much sun exposure when the plant is covered in an oil-based spray can burn the leaves.  It’s best to use this spray right before nightfall or in shaded areas.  Re-treat as needed.

As a preventative, you can leave a few drops of eucalyptus oil in places where ants may become a problem.  They don’t like the smell and will likely stay away.

Hot Chili n’ Garlic Spray

This homemade insecticide spray will deter most leaf-eating insects and Scale.  As with any herbal, plant, or oil-based spray, you’ll want to test it on a small patch of your garden before applying to everything.  If the concoction is too strong, you’ll know within 24 hours.  Your plant will shrivel or show signs of dying.  Try diluting it a bit and test again.

Hot Chili n’ Garlic Spray Recipe:

  • 4 very hot fresh chilies (ghost, red, jalapeno, etc.), coarsely chopped
  • 4 large white onions, coarsely chopped
  • 2 bulbs fresh garlic, coarsely chopped
  • 2 Liters filtered water
  • ¼ cup organic dish soap

Place all the chopped vegetables in a large, screw-top container.  Mix the soap with the water until it’s thoroughly blended and bubbly.  Pour the soapy water over the chopped vegetables.  Let steep for twenty-four hours.  Strain into a spray bottle and apply in a mist onto your garden where the infestation is likely or already in progress.

Not only is this spray affective, it will make your garden smell like a Mexican restaurant!  But don’t worry, the smell dissipates quickly.

Here is a YouTube video tutorial by DomsGreenThumb that will walk you through a small-batch variation of this recipe.

This list is by no means exclusive.  It’s just a start.  There are recipes out there for organic pest control ranging from a tobacco solution sprayed on the leaves, to populating your garden with ladybugs.  If one doesn’t meet your needs, try another or a combination until the only things you’re picking out of your garden are beautiful fruits, vegetables, and flowers.







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