Organic Pest Control – Natural Ways Of Controlling Pests

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Organic Pest Control

One of the greatest challenges to an organic gardener is organic pest control.  Harsh chemicals are not needed, despite what the big corporations tell you.  Organic pest control doesn’t have to include expensive chemical pesticides.  It starts with becoming an organic gardener or farmer.

Pests can range from so small you can’t see them, to as large as a moose.  These pest can include insects, animals and weeds. The insects range from the tiny thrips to the large hornworm.  Animals can range from slugs to mice up to deer or even a moose.  Weeds are any plants that grow where you don’t want them.

Bacteria, fungi and other organisms can cause disease.  Some are soil born diseases and some are the result of damage caused by insects.  Improper use of fertilizers, pesticides and herbicides can also damage your plants.

Organic Pest Control Practices

You have to know what is causing a problem in your garden before you can fix it.  Some insect damage can look like a disease, especially if you don’t see the insects.  Lack of proper nutrients can also look like disease.  The use of chemical fertilizers, pesticides and herbicides can also cause problems.


There are a multitude of organisms and insects that can be in your garden.  Not all are harmful though.  Some are beneficial like earthworms, ladybugs, bees, nematodes and others.  Some that can cause damage include organisms like ants, beetles, flies, moths and butterflies.

Insect Damage 

organic pest control - caterpillar damageThe most obvious damage is going to be what is most visible, chewed leaves, stems and flowers.  Some of the pests will be easy to identify, like the Japanese beetle or the tomato hornworm.  Other insects are harder to identify.  Some, like cutworms will cause their damage at night and burrow into the soil during the day.  You can suspect these if you have damage only at night or your plants get cut off at the ground.

Sucking insects insert their mouth parts into plant tissue and suck out the juices.  They can be hard to identify.  They include aphids, mites, leafhoppers and thrips.  Damage will be in the form of misshapen leaves or flowers.  Younger leaves may appear curled or flowers may only partially develop. The insects usually will gather on the underside of leaves.

Some insects like the squash borer bugs can be extra hard to identify.  They bore into the plant and feed from the inside.  Usually the plant leaves will wilt as a first sign, at first just in full sun, then continuously.


Plant diseases are hard to diagnose in some cases.  Many can only get identified by lab analysis.  Symptoms can be spots on leaves, flowers or fruits. You might also have sudden loss or wilting of a plant or part of the plant; or just stunted growth.  The use of garden chemicals can cause some of the same symptoms.

Prevention of Pests

The first step in organic pest management is prevention.  That is the goal, but it is unlikely you will be able to prevent all pest problems.  Weed seeds and disease organisms can lay dormant for years. They are waiting for the right conditions.

Disease needs 3 things:

  • A disease organism
  • A susceptible plant
  • The right environmental conditions.

Disease organisms are carried by insects or plant material from a diseased plant.  Good sanitation practices can limit some of the problems.  If you have a diseased plant in the garden, get rid of it.

You can reduce the second thing  by planting disease resistant plant varieties.  You also want to keep your plants healthy because a healthy plant is less likely to get a disease.  That means giving your plants the proper amount of nutrients.  Not excessive, but the proper amount.  Giving a plant too much nitrogen may cause a lot of growth but can leave the plant vulnerable to disease.

Environmental conditions get controlled somewhat with proper watering and spacing of plants.  Some diseases spread in standing water, some just need high humidity.  Trickle irrigation can help prevent some diseases.  Proper spacing gives good aeration around your plants.  This makes the spread of disease from plant to plant is less likely.

Crop rotation is necessary to keep disease and pests down.  Rotating your crops keeps pathogens harmful to a specific plant from building up.  Growing the same crop in the same spot year after year is asking for problems.

Homemade Organic Pest Control

Some pests can be removed  by hand.  Some of the caterpillars come to mind.  Just pull them off and dispose of or give to the chickens.  Aphids can be removed from some plants with a spray of the hose.  A vacuum cleaner works for some.  A fence, netting or even traps may be required for the larger pests.  There are traps for some of the smaller organisms as well.

Slugs can be controlled with a trap made of a shallow dish filled with beer.  Diatomaceous earth is used to control slugs and other soft bodied creatures.

Organic Pest Control Products

Homemade pest controls like garlic/pepper teas or even just liquid dish soap are common.  Insecticidal soaps and horticultural oils are available to help with some insect problems.  Keep in mind though, too much use of even organic pest control products is not good. It can kill your beneficial organisms and cause even more problems.

Biological Pest Controls

Biological controls are just natures way of dealing with some of the pests in the garden.  They can range from bacteria like Bacillus thuringiensis (Bt), to bird or bats.  I let my guinea hens roam the yard plus a couple ducks.  They do a pretty good job of keeping some of the bugs down.  My chickens are good for beetle and grub control.  They are not allowed in the garden or their scratching will uproot everything.

organic pest control - waspThere are spiders, flys, beetles, wasps and others that help control some pests in the garden.  Planting plants that attract beneficial insects is another way of controlling your pest problem.  Usually that is going to be a native plant.  Native wildflowers usually attract beneficial insects.  Companion planting is the term used for this type of planting.  Companion plants attract beneficial insects or repel pests.  They can also add nutrients to the soil for other plants.

One of the best ways of reducing pest problems in your garden is to be organic.  That will make it a diverse growing environment with rich soil and healthy plants.  This  recreates what nature does on the forest floor.  Read my articles on Organic Gardening and Lasagna Gardening.

Here is a list of some harmful insects and ways of control them.

Aphids: Insecticidal soap, horticultural oil, ladybugs

Beetles (most): Poultry, neem, handpicking

Cabbage root maggot: Crop rotation, beneficial nematodes, diatomaceous earth

Cabbageworm: Bt, handpicking, row covers

Colorado potato beetle: Poultry, neem, handpicking

Corn earworm: Bt, horticultural oil, beneficial nematodes

Cucumber beetle: Poultry, neem, handpicking

Cutworm: Rigid collars, Bt, diatomaceous earth

Harlequin bug: Handpicking, good garden sanitation, neem

Onion root maggot: Crop rotation, beneficial nematodes, diatomaceous earth

Slugs and snails: Handpicking, iron phosphate slug bait, diatomaceous earth

Squash bug: Handpicking, good garden sanitation, neem, late planting

Squash vine borer: Growing resistant varieties, crop rotation, beneficial nematodes, late planting

Stink bug: Handpicking, good garden sanitation, neem

Tomato hornworm: Bt, handpicking, row covers

Whitefly: Insecticidal soap, attracting beneficials, horticultural oil