Blog Archives

Winter Woes on Woody Landscape Plants: Winter Drying

The UK Plant Disease Diagnostic Laboratory (PDDL) has received many broadleaf and needled evergreen samples with discolored foliage recently.  Despite relatively mild weather during much of the winter thus far, extremely low temperatures, low humidity, and strong winds during the

Posted in Landscape Trees & Shrubs

Hackberry Psyllids Cause Bumpy Leaves

Hackberry trees are fairly common in the landscapes of Kentucky. Some of them were purposefully planted after the fall of the elms from Dutch elm disease, though others seem to spring up on their own. Regardless of their provenance, when

Posted in Landscape Trees & Shrubs

August is Tree Check Month!

The USDA has declared August as “Tree Check Month” to foster awareness of the Asian longhorned beetle (ALB), an invasive pest that could be devastating to Kentucky forests and landscapes. Currently, the pest is not known to live in the

Posted in 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

Fluffy Maple Leaves? Check for Cottony Maple Leaf Scale!

Red and silver maples can be host to an interesting looking scale insect, the cottony maple leaf scale. Entomologists tend to be on-the-nose when naming things, so unsurprisingly this scale insect specializes in feeding on leaves and, at one point

Posted in Landscape Trees & Shrubs

Hanging by a Thread

Dead, curled leaves dangling by fungal “threads” are typical of a disease called thread blight.  This disease is more common in eastern Kentucky, where it has been observed on apple, cherry, and viburnum.  Other potential hosts include cotoneaster, dogwood, gooseberry,

Posted in Fruit, Landscape Trees & Shrubs

Cupped Boxwood Leaves from Boxwood Psyllid

If you are noticing cupped leaves at the tips of new boxwood growth, you are noticing the symptoms of boxwood psyllid damage. Not to worry though; this boxwood bug may cause unsightly leaves to form, but the damage is rarely

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

Boxwood Blight

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

Posted in Landscape Trees & Shrubs

Late Season Oak Symptoms

Tree pests Oaks are mighty trees that we love to have in the landscape. Due to the fact that they are mostly native, and they are long-lived and sturdy, we can find many different kinds of insects and mites feeding

Posted in Landscape Trees & Shrubs

Transplant Shock: Disease or Cultural Problem?

Autumn will soon arrive in Kentucky, and it 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

Posted in Landscape Trees & Shrubs

“Wet Feet” of Ornamentals

“Wet feet” is the common term for a condition that affects plant species intolerant of wet growing conditions. This problem occurs when soils become saturated in water, which ultimately causes roots to suffocate. Once root damage occurs, plants decline and

Posted in 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

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