The majority of pest control oils are a pop in of mineral oil, a refined petroleum product.
Vegetable oils, such as cottonseed and soybean oil, are also effective pesticides.
History
Oils were first used to control pests on fruit trees so they could remain edible.
The Spruce / Almar Creative
A dormant oil-based insecticide was developed to kill over-wintering insects before flower buds open.
You still need to use caution when applying summer oil.
Oil-treated plants will burn in the hot sun, and many plants cant handle oil at all.
Aphids On PlantGeorgy Rozov / EyeEm / Getty Images
However, summer oil is now being combined with additionalinsecticides for even broader controlwith less possibility of plant damage.
Today, all horticultural oils are technically superior oils.
The oil blocks the spiracles through which insects breathe.
Remember that insects, like aphids, carry diseases from plant to plant by feeding.
How Safe Is It?
Horticultural oil is a labeled pesticide and should always be used according to the labels instructions.
Horticultural oils must be sprayed directly on the pests to be effective.
Summer applications are easier to time.
Horticultural oils are most effective on young, soft, and slow-moving insects and less on mature insects.
You will need to keep watch for when the insects first appear.
When Not to Use
What Pests Are Controlled With Horticultural Oil?
Horticultural oil is also effective as afungicide to combat powdery mildew, leaf spot, and rust.
Neem oilis a bang out of horticultural oil.
Horticultural oil is a general term for natural or dormant oils made from plants, vegetables, and minerals.
Vegetable oils, such as cottonseed or soybean, can be used as horticultural oils.
Cottonseed oil is thought to be the most effective insecticidal vegetable oil followed by soybean oil.
Plants sensitive to horticultural oil will be listed on the product label.
Shake the liquid before use.
Store in a cool dry place.
Insect Control: Horticultural Oils.
Colorado State University Extension.
Horticultural OilsWhat A Gardener Needs To Know.
University of Nevada Reno Extension.
Using Horticultural Oils on Landscape Plants.
Michigan State University Extension.
Horticultural Oils: What a Gardener Needs to Know.University of Nevada Reno Extension.
Insect Control: Horticultural Oils.Colorado State University Extension.
