Definition - What does Horticultural oil mean?
In botany, horticultural oil refers to an oil made from a mixture of fish oil, vegetable oil and petroleum products. This oil has been shown to control and treat various types of plant-borne diseases as well as garden insect pests. In some cases, the oil is mixed with an emulsifying agent before being incorporated with water to be used as a spray.
MaximumYield explains Horticultural oil
Unlike traditional insecticides, horticultural oil does not damage the plants if used properly. This oil has also been shown to disrupt the insect’s egg metabolism, preventing them from propagating. In some cases, the oil can also prevent insects from feeding, causing death by suffocation. While it is considered safer than traditional insecticides, horticultural oil should never be applied in hot temperatures of 100 degrees F or more. This is particularly applicable to drought-stressed plants that are more prone to damage. Additionally, it is not advisable to apply horticultural oil during freezing temperatures because the emulsion cannot hold together in colder climates, resulting in an uneven coverage.
This oil has been shown to be particularly effective when used against the following insects: whiteflies, thrips, spider mites, scale, mites, mealybug, leafhoppers, caterpillar eggs, aphids, and adelgids. In some cases, this product can also be used against powdery mildew, especially when mixed with baking soda.