Plant Pests and Diseases

Olive trees are migrating north

By Mike Darcy — Posted November 29, 2023

Olive trees are now available at most local garden centers and in most cases, have seemed to grow well in our local conditions.

Progress towards effective Phytophthora root rot control

By Jerry Weiland — Posted October 31, 2023

OSU research shows different approaches required for management of common rhododendron disease.

The genetic revolution comes home

By Melodie Putnam — Posted September 5, 2023

Researchers seek new ways to make use of whole genome sequencing in plant production.

The replacements

By Erica Browne Grivas — Posted September 5, 2023

Over-reliance on certain trees often prompts the need to turn to newer varieties in place of faltering favorites.

Get to know the horticultural researchers at OSU and USDA Many programs focus on nursery, greenhouse, landscape and related crops at Oregon State University (OSU) and the Horticulture Crops Research Laboratory at the Agricultural Research Service (USDA ARS), the principal in-house research agency of the United States Department of Agriculture. Here are some of the […]

Going with the flow

By Lloyd Nackley — Posted March 24, 2023

Research on plant hydraulics helps explain the effect of drought stress on shade trees By Sadie Keller, Rebecca Sheridan, Scout Dahms-May, Carolyn Scagel and Lloyd Nackley In Oregon’s Willamette Valley, the heart of the nursery industry, rainfall is scarce during the summer and humidity is low. The plant stress resulting from the low soil moisture, […]

The tribulations of big trees

By Jon Bell — Posted March 24, 2023

Growing bigger trees that will flourish in a changing climate takes a long-game approach For decades, tree-lined streets across the country — largely in the Southeast — would erupt in the bright white blossoms of Callery pear trees (Pyrus calleryana) every spring. Affordable, fast-growing and easily shipped, the trees had become the darlings of landscapers, […]

Boxing out boxwood blight

By Jon Bell — Posted December 27, 2022

Growers must work vigilantly to keep the fungus that causes boxwood blight out of their nurseries Boxwood is one of the most popular landscaping plants around. It’s evergreen and pretty, it provides natural privacy, it’s easy to maintain and it can be shaped into attractive ornamental topiaries. In fact, so popular is boxwood that it’s […]

Don’t get burned by charcoal rot

By Jerry Weiland — Posted November 2, 2022

Soilborne fungus can afflict hebes and a wide range of other host plants Hebes (pronounced heebees) are an interesting group of evergreen shrubs, mainly from New Zealand, although there are also a few from South America and French Polynesia. Botanically, they are now placed in the genus Veronica, but many will know them by their […]

The fight against flatheaded borers

By Lloyd Nackley — Posted October 3, 2022

Oregon State University researchers from the Nackley (nursery) and Wiman (orchards) programs have teamed up with scientists from across the country to study the biology and management of flatheaded borers. Flatheaded borers are beetles, from the order Coleoptera and the Buprestidae family, that can be devastating pests of ornamental trees grown in nurseries, transplanted landscape trees, trees grown for wood or other products, and fruit and nut crops.