Rhododendrons, lilacs potentially infected with pathogen to be monitored, removed

ST. CLAIRSVILLE — Plants shipped to local stores are infected with a pathogen that is dangerous to oaks and other trees.

On July 16, the Ohio Department of Agriculture in coordination with the U.S. Department of Agriculture Animal and Plant Health Inspection Service issued a press release indicating that sudden oak death caused by Phytophthora ramorum was detected on rhododendron and lilac plants shipped to Walmart and Rural King stores throughout the state. They have since learned that potentially infected plants were shipped to Walmart and Rural King stores in southeastern Ohio cities including St. Clairsville and Athens, Chillicothe, Gallipolis, Jackson, Logan, Marietta, New Boston, South Point, Waverly, West Union and Zanesville.

Ohio State University Extension, the Ohio Department of Natural Resources Division of Forestry, U.S. Forest Service and local Soil and Water Conservation Districts are working with the ODA and USDA APHIS to provide support to customers who purchased rhododendron plants from Walmart or Rural King stores with the potential to spread sudden oak death to native woodlands in the region. Phytophthora ramorum, the pathogen that causes sudden oak death, has resulted in widespread mortality of oaks and other species in coastal areas of California and Oregon.

Dan Lima, OSU ANR Extension educator, said even though there are no known instances of sudden oak death establishment in eastern forests, it is important to reduce the possibility of this potentially deadly disease from becoming established in oak-dominated forests in southeastern Ohio. Oak trees contribute greatly to Ohio’s $26 billion forest products industry, provide vital habitat for many wildlife species, and are important for tourism in southeastern Ohio.

The ODA and partners are encouraging homeowners who purchased rhododendron or lilac plants from Walmart or Rural King between March 1 and June 1 to monitor the plant for signs of disease, including leaf spots and shoot dieback and to properly dispose of the plants. The recommended method of disposal is double-bagging, including the root ball, in heavy duty trash bags for disposal into a sanitary landfill. Do not compost or dispose of the plant material in municipal yard waste. Garden tools used on any affected plants should be sanitized with 10 percent bleach solution (one part bleach to nine parts water) for 30 minutes.

If you think you purchased any of these potentially infected plants, contact Lima at lima.19@osu.edu or 740-695-1455 for assistance with reporting, monitoring and proper disposal of potentially infected plants.