The Ohio Department of Agriculture (ODA) has announced in an official press release a confirmed interception of the plant disease-causing pathogen Phytophthora ramorum in Ohio.

P. ramorum is a water mold organism that causes ramorum blight on over 100 host plants, including rhododendron and lilac, and sudden oak death (SOD) in coastal areas of California and Oregon.  SOD has proven to be deadly in California and the Pacific Northwest on oaks (Quercus) and tanoaks (Notholithocarpus). On other hosts, this pathogen causes leaf spots and branch dieback.

Though this pathogen was found on rhododendrons and lilacs intercepted here, there was no shipment of oaks with SOD.

Gardeners and homeowners who have recently purchased a rhododendron from Walmart or Rural King should monitor the plant for signs of disease, including leaf spots and shoot dieback. It is also advised that Ohioans who purchased rhododendrons or lilac plants from these stores between March and May of this year to dispose of them to prevent further spread of the disease. Plants can be destroyed by burning, deep burial or double-bagging the plant, including the root ball, in heavy duty trash bags for disposal into a sanitary landfill (where allowable).

Consumers should not compost or dispose of the plant material in municipal yard waste. Garden tools used on any affected plants should be sanitized with bleach or 91% (or higher) alcohol before they are used again.

Excerpts for this alert were taken from the following sources:

The Ohio Department of Agriculture Alert

OSU Buckeye Yard and Garden