According to the Indiana Department of Natural Resources (DNR), the threat to oak trees across the state has grown.

The DNR confirmed on Wednesday that more than 70 Walmart stores and 18 Rural King stores in Indiana have received rhododendron plants that are infected with sudden oak death (SOD), a fungal pathogen that kills trees.

Department of Entomology and Plant Pathology workers have visited stores across Indiana in order to destroy stock that has been found to be infested with the disease as well as quarantine any stock that is symptomatic.

Approximately 1,500 infested rhododendrons have been destroyed and another 1,500 have been pulled from stores, the DNR said.

If you have purchased rhododendrons in the last four weeks from either a Walmart or a Rural King store, destroy them, or call 1-866-NO-EXOTIC (663-9684) or the local county extension office at 1-888-398-4636 for instructions.

To learn more about SOD, visit the USDA’s website.

This is an ongoing investigation.