Virginia Green is now scheduling our early-to-late winter Horticultural Oil applications. These treatments provide control to a number of pests such as scales, mites, and aphids on trees and shurbs.
While it has been suggested that oils smother or suffocate small insects and mites that cannot crawl out of it, the disruption of cell membranes and the resulting desiccation of the pest is another mode of action. Oil is a very environmentally safe and effective product. Insects generally do not build resistance to the oils.
Horticultural Oils work best when they are composed of tiny droplets. Total coverage is essential for effective control. The oil must cover the insects and eggs that overwinter within the crevices of the bark, around the branch collars, bud union, etc. Insects and mites are more vulnerable to Horticultural Oil when applied as a delayed dormant spray in early-to-late winter because they have resumed their activity and growth. Actively growing insects or mites are more susceptible than dormant ones.
Our recommendation is 1 or 2 applications, depending on the population. One application with complete coverage will be sufficient as a preventative step. However, when there are high populations of pests such as Scale, we need to apply two applications of horticultural oil separated by several weeks.
Please contact Troy Hall to receive a free estimate and diagnosis of your landscape this fall.
Troy Hall: 804-334-1521