IDNR Issues Warning About Plant Shipments Contaminated with Sudden Oak Death

The Indiana Department of Natural Resources is alerting residents that a number of plant shipments in the state that were contaminated with a fungal pathogen that kills oak trees.

This is the first time this infection has been spotted in about 10 years.

The IDNR confirmed that more than 70 Wal-Marts and 18 Rural King stores in Indiana received rhododendron plants infected with the fungal pathogen referred to as Sudden Oak Death (SOD). Contaminated shipments were also sent to 9 other states.

Rhododendron degronianum

Workers from the Department of Entomology and Plant Pathology have been visiting stores across Indiana to destroy any infested stock and to quarantine stock that’s symptomatic.

The division has made this its top priority. Any quarantined material not infected will be released following testing at Purdue University.

SOD travels in more than a hundred species of host plant material. It causes some browning of the leaves in the host but does not kill it.

As of Wednesday, the DNR had destroyed approximately 1,500 infested rhododendron plants and pulled another 1,500 from stores. Officials also ordered stores to stop selling rhododendron for the time being.

Oak Tree

SOD has not been established in the Midwest, to date, but it has killed large tracts of oaks on the West Coast. The fungal pathogen can kill a standing oak, which could happen if SOD-positive rhododendron is planted within about 6 feet of the tree.

If you have purchased rhododendron from Wal-Mart or Rural King within the last four week, destroy them. You can also call 1-866-No-Exotic (663-9684) or your local county extension office at 1-888-EXT-INFO(398-4636) for further instructions.

This is an ongoing investigation, and guidance could change as more information is gathered. For more information, follow the links provided above.