What is Horticultural Oil?

Horticultural oil is a type of petroleum-based or mineral oil that is used in horticulture and agriculture to control pests, diseases, and mites on plants. It works by smothering the insects and their eggs, and it can also help to control certain fungal diseases by removing the waxy surface layer of fungal spores, reducing their ability to spread. 

Horticultural oils are highly refined and are considered safe for use on plants, but care should be taken to follow the label instructions for dilution and application to avoid damaging the plants.