Have you dealt with mite, scale, or adelgid infestations in years past? When it comes to controlling any of these three pests, dormant oil is a cost-effective solution. It works by dissolving and penetrating the waxy shells of mites and insects, which eventually shrivel and die. 

Dormant oil generally works best on soft-bodied pests. But in the case of scale, armored scales are more susceptible to dormant oil than soft scales. Armored scales that overwinter as adults (such as euonymus scale) rather than eggs (such as pine needle scale and oystershell scale) are especially susceptible to dormant oil.

You can also apply dormant oil to eggs for population control. Spray to drip for maximum coverage, because only the eggs penetrated by the oil will die. Keep in mind that oil strips the blue waxy bloom on some evergreen needles, including blue spruce. 

Late winter or early spring is a good time to apply dormant oil, once the temperature is above 40°F for at least 24 hours. If you know you’ll be making an herbicide application on the plant as well, you might wait to apply the oil at the same time.

Twospotted Spider Mite Damage

We also offer a product called Brandt TriTek Oil, which is a little different than other dormant or summer oils. It’s pre-emulsified to produce more stable and efficient results. Brandt shears the droplets to 1/14 the original size, which allows for a thin, even coating of oil to be applied to both the plant and the pest. It’s more effective at killing the pest while being safer to the plant.

What about soft scale control? Though dormant oil isn’t an effective solution, a systemic is. Both Safari and imidacloprid provide excellent control of soft scales. Safari is more water-soluble and therefore moves up the tree faster than imidacloprid. But imidacloprid is more cost-effective. Choosing between the two is a matter of determining how quickly you need to see results.

As always, reach out to your ATS sales representative for consultation on which product will best meet your needs.