Blog Archives

Laurel Wilt Disease: A Threat to Kentucky Sassafras Trees

Laurel wilt is a new disease that was recently detected in southwestern Kentucky. This disease, which is transmitted by the redbay ambrosia beetle, has the potential to rapidly kill sassafras trees. Currently no management options are available for this disease.

Posted in Forest Trees, Landscape Trees & Shrubs

Cherry Leaf Spot

Cherry leaf spot is a fungal disease of sweet, sour, and ornamental cherries. While this leaf disease is rarely a death sentence for trees, it can result in reduced blossoms, weakened trees, and increased risk for winter injury. Cherry Leaf

Posted in Fruit, Landscape Trees & Shrubs

Anthracnose Diseases on Shade Trees

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

Posted in Landscape Trees & Shrubs

Cedar-Hawthorn Rust

Cedar-hawthorn rust is a common disease of apple, crabapple, hawthorn, and ornamental pear in Kentucky; it also affects quince, mountain ash, pear, and serviceberry.  The pathogen overwinters as galls on its alternate hosts, cedar and juniper. Removal of these galls

Posted in Fruit, Landscape Trees & Shrubs

Volutella Blight of Boxwood

Volutella blight is the most common disease of boxwood in the landscape. Volutella blight is caused by an opportunistic fungal pathogen that attacks leaves and stems of damaged or stressed plants.  Winter injury, poor vigor, and wounds increase risk for

Posted in Landscape Trees & Shrubs

Dogwood Anthracnose Spotted

Anthracnose of dogwood is a common problem in Kentucky. Symptoms on landscape and forest dogwoods often first appear during wet periods in late spring. If left unmanaged, the pathogen spreads, eventually resulting in plant death.  Selection of resistant varieties and

Posted in Forest Trees, Landscape Trees & Shrubs

Bacterial Wetwood and Slime Flux

Bacterial wetwood and slime flux refer to bacterial “ooze” that runs down trunks of trees.  Oozing fluids are the result of a bacterial infection known as bacterial wetwood (Figure 1). Advanced development is called slime flux, in which a foul-smelling,

Posted in Landscape Trees & Shrubs

Last Year’s Ornamental Diseases Equal This Year’s Disease Risk

Disease presence last year can indicate a risk for the same disease this year. Many pathogens overwinter on infected plant material or as pathogen survival structures. Poor sanitation practices can lead to an increased risk of these diseases in the

Posted in Landscape Trees & Shrubs, Ornamentals

Avoid Introduction of Boxwood Blight into the Landscape

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

Posted in Landscape Trees & Shrubs

Rainy Season Equals Phytophthora Disease in Ornamentals

Spring rains can create growing conditions that are devastating to most landscape plants.  Wet soils are favored by a group of pathogens called water molds, or oomycetes, which cause a range of root and stem diseases. Water molds are found in

Posted in Landscape Trees & Shrubs, Ornamentals

Leaf Scorch and Winter Drying of Woody Plants

Leaf scorch occurs whenever water needed for growth and health of plant foliage is lost from leaves faster than it can be replaced from soil. Any factor that interferes with uptake or movement of water through plants cause water deficiency

Posted in Landscape Trees & Shrubs

From Tree Thief to Holiday Tradition: The Story of Mistletoe

Once autumn leaves have fallen, mistletoe becomes highly visible on large trees throughout Kentucky. Phoradendron, the scientific name for Kentucky’s most common type of this parasitic plant, means tree thief. These small leafy plants are commonly found on twigs and

Posted in Forest Trees, Landscape Trees & Shrubs

Landscape Sanitation: Clean Up for Clean Plants

Autumn has arrived in Kentucky and, as leaves will soon begin to change color and fall from trees, it is time to focus on landscape sanitation. Good sanitation practices can help reduce disease-causing pathogens.  These organisms can survive for months

Posted in Landscape Trees & Shrubs, Landscapes, Ornamentals

Transplant Shock: Disease or Cultural Problem?

Autumn has arrived in Kentucky, and now is one of the best times to plant new trees. Cool-season planting allows trees to “focus” on root system development. Woody plants may take as long as 3 to 5 years to establish

Posted in Landscape Trees & Shrubs

Bacterial Leaf Scorch Can Torch Landscape Trees

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;

Posted in Landscape Trees & Shrubs