Today’s vegetable gardeners are becoming more and more aware of the importance of using organic products, and pesticides are no exception.
Using organic pesticides instead of the chemical types is very important for protecting the environment, gardener well-being, and for a fresh harvest.
If you are new to growing your own vegetables, here are a few useful organic pesticides that will handle many issues with those pesky critters.
Using even organic pesticides can come with a price, so they should be used only as a last resort.
Insecticidal soap is made from potassium or sodium salts that are combined with fatty acids. It must come into direct contact with the pest insect in order to be effective, and loses it’s effectiveness once it has dried.
Insecticidal soap works by penetrating the insects outer shell, and disrupting the tissue cells. It is one of the safest organic pesticides because it is non-toxic to humans and animals, leaves no residues, and can be used right up to harvest.
Use caution when using insecticidal soap as it can burn plants, if used excessively.
Bacillus Thuringiensis (Bt)
Bt is a bacteria that comes in a powdered, or liquid form and sprinkled/sprayed around and on plants. There are over 80 different types of the Bt bacteria used as pesticides.
The insects must ingest the powder, or spray, which releases toxins in the insect’s stomach. Bt is most commonly used for caterpillars, such as hornworms and cabbage moths.
The toxins will cause the insect to become ill and stop eating – resulting in death. Bt is safe to use around humans, pets, birds, and most types will not harm bees.
It can irritate sensitive skin and breaks down quickly in sunlight. It usually takes a couple days for Bt to cause an insect to stop eating and die.
Thuricide is a great choice of Bt to use in the vegetable garden
Neem oil is derived from the fruit of the neem tree, and comes in a liquid spray. Neem oil affects the hormonal system of immature insects, and prevents the insect from reaching the mature stage. It works best for insects that undergo metamorphosis.
Neem oil will wash away after rain or heavy watering. It is non-toxic to humans, but pets should be kept away from sprayed leaves until they are dry. Neem oil can kill beneficial insects as well as pests, so use caution when applying.
Horticultural oil is a highly refined petroleum that should be diluted with water and sprayed on plant leaves. The spray will coat and suffocate insects. It is safe to use around humans, birds, pets, and does not leave a residue.
Horticultural oil works best against soft bodied insects such as aphids. It can burn plants if used excessively. There are several different grades of horticultural oil, make sure you are using the appropriate type for your situation.
Rotenone comes from the roots of tropical plants, and comes in a powdered form.
It should be dusted around and on plants. Rotenone deprives oxygen to the insect’s tissue cells when ingested.
It is a broad spectrum pesticide, and will/can kill most insects that come in contact with it. Because of this, rotenone should only be used as a last resort for heavy infestations of pest insects.
Diatomaceous earth comes from the fossilized remains of algae. It is naturally occurring and comes in a very fine powder. Diatomaceous earth causes insects to dehydrate by affecting the exoskeleton of the insect. It works really well for eliminating snails and slugs. Dust around and on plant plants and plant leaves.
Diatomaceous earth will need to be re-applied after rain or heavy waterings. It can be slow-acting in eliminating pests, taking up to 10 days to affect and kill them. Diatomaceous earth will also affect beneficial insects as well.
Be sure to use a dust mask when working with diatomaceous earth, as the fine dust particles can be inhaled into the lungs.
A form of diatomaceous earth is used in swimming pool filtration – do not use this form as an insecticide. This form has been heat and chemically treated, and is very dangerous to breath.