Kentucky’s landscapes are populated by many trees that are susceptible to bacterial leaf scorch. This disease may not kill trees instantly, but over time, it can have devastating effects. Pruning and reducing stress can prolong the life of infected trees;…

Water is an essential component to plant mass and is vital to growth, carbohydrate production, and nutrient transport. During periods of below-average rainfall or when rain distribution is uneven, plant health may decline (Figure 1). Drought conditions or inadequate water…

Woody trees and shrubs may exhibit decline resulting from the stresses that can occur during their lives. Stress may be the result of improper plant or site selection, incorrect planting or maintenance practices, or poor soil conditions. Injury from equipment,…

Boxwood blight can be devastating to American boxwood cultivars, which are common in the Kentucky landscape. Complete defoliation can occur within a week and plants can die within a single growing season. Use of tolerant cultivars, cultural practices, and fungicides…

Dogwood is a popular landscape tree throughout Kentucky. However, once infected with powdery mildew, trees can develop an unattractive appearance. The disease is most prevalent during periods of high humidity and in landscapes with reduced air circulation. Some cultivars are…

Barklice that is. While that sounds alarming, and brings to mind blood-sucking lice, barklice are not lice and are very different from the parasitic lice that can infest people and livestock. Barklice cause concern when they are seen in large…

The stress of hot, dry conditions in midsummer can prompt leaf scorch in many landscape trees. However, extensive canopy dieback or tree collapse, particularly on one side of a tree, may indicate Verticillium wilt disease.  Numerous cases of this vascular…

Rhizosphaera needle cast is often to blame for brown or thin spruce in the landscape. In Kentucky, Rhizosphaera needle cast is the most common disease of spruce; it also affects some pine species. This disease causes needle drop on lower…

Bagworm season is upon us in Kentucky. Depending on where you live, the hatching could have occurred anywhere from just in the last few days to a couple of weeks ago. If you want to monitor for their emergence next…

Blue spruce and Norway spruce are popular landscape plants in Kentucky. However, many factors can cause spruce trees to cast (shed) needles. Casting may be the result of environmental stresses (heavy soil, poor drainage) or fungal diseases. In Kentucky, Rhizosphaera…

The term anthracnose refers to the dark blotching (necrotic) symptom common to these diseases.  When expanding leaves are affected, leaf distortion frequently results (Figure 1). Defoliation (leaf drop) often occurs during severe infections. The disease is generally not fatal, and…