For your trees and shrubs, one of the most important and environmentally friendly applications of the year is being done now! Dormant oils are one of our best tools against the unwanted pest population in your landscape shrubs. Insects such as scale, mites, and aphids — which have no natural predators active in winter — are susceptible to dormant oil treatments.

Things to know before applying dormant oils:

• Apply only when temperatures are above freezing and will remain above freezing for 24 hours after application.
• Do not apply to drought-stressed plants.
• Avoid application when rain is expected within 24 hours.
• Do not apply to blue-green or silver-foliaged conifers — the oil can permanently discolor the foliage.

Soft-Bodied Scale on Crape Myrtles: What Homeowners Need to Know

One of the most damaging pests affecting crape myrtle trees in West Tennessee is soft-bodied scale. This invasive insect was introduced to the United States through imported ornamental plants and has become a widespread problem in the Memphis area.

Soft-bodied scale insects feed by sucking sap from the tree. When populations grow large, they can weaken the tree, slow growth, and in severe cases, cause dieback or plant death.

Homeowners often notice:

• White, fuzzy patches on bark or branches
• Sticky residue (honeydew) on leaves or surfaces below the tree
• Black coating on leaves, patio furniture, or sidewalks

The sticky honeydew allows a black fungus called sooty mold to grow. Once established, sooty mold cannot be easily washed off.

The most affordable and effective treatment is applying dormant oil during winter, after the tree has dropped its leaves. Dormant oil works by smothering the scale insects.

A similar type of scale insect is also commonly found on holly trees.

Mites are another common winter pest on evergreen shrubs. Spider mites and other species can cause stippling and discoloration on foliage even during cooler months.

Roses are frequently affected by aphid colonies that overwinter on canes and buds. A dormant oil application in late winter can significantly reduce aphid pressure at the start of the growing season.

For pest control on many of our shrubs in the Memphis area, dormant oils give you the biggest bang for your buck. They are cheap and safe for beneficial insects, birds, and the environment when applied correctly.