Horticultural Oils have been used in the home landscape and orchard pest control for decades, but their use has increased in recent years as environmental awareness grows.
Years ago, horticultural oil was known as dormant oil and was only applied when plants were dormant. These older oils were very heavy and would cause damage to foliage if applied during the growing season. Today’s horticultural oils are much lighter and safer for plant foliage, but still must be used with caution to avoid burning foliage.
Insects don’t have lungs. They breathe by a different mechanism than mammals; a series of external openings on their body called spiracles. Horticultural oil kills insects by blocking these spiracles, which suffocates the insect. Horticultural oils will also disrupt the metabolism of insect eggs, preventing them from maturing into adults.