Certain refined oils, diluted with water and applied as sprays, are very effective in the control of many plant pests. Oils are great in controlling insect and mite problems, but can also control certain diseases, such as powdery mildew. Although they may be called by different names, they are generally referred to as horticultural oils.
These oils are a very important tool to integrate into biological pest control programs as they pose very few risks to people or beneficial insects. Toxicity is minimal, especially compared to alternative pesticides. Oils control pests through asphyxiation, by interfering with normal metabolism or by disrupting how an insect feeds.
When used in late winter or early spring before plants break dormancy, they are usually mixed at a higher concentration and referred to as dormant oil sprays. These sprays are effective in treating holly, spruce, fir, hemlock and other evergreen species for pests like mites, scale, and adelgids. You should not spray blue spruces as the oils can strip the coloration from the plant. Once plants are in active growth, oils should be mixed at a lower rate and are referred to as summer oil or superior oil sprays. Seasonal outbreaks of aphids, mealybugs and lacebugs can be controlled quite easily. However, caution should be taken with higher temperatures, with certain plant species and plants under stress. Used properly, horticultural oils can play a safe and vital role in pest management. Let Snow Creek Landscaping provide these applications for you.