Sudden Oak Death
The Division of Entomology & Plant Pathology intercepted plants containing a fungal pathogen that kills oak trees, sudden oak death (SOD) in May 2019. This was the first time in about 10 years.
Inspectors detected SOD (Phytophthora ramorum) in several varieties of rhododendrons being sold in Columbus, Noblesville, South Bend, Sullivan and Tippecanoe.
SOD has killed large tracts of oaks on the West Coast. SOD has not been established in the Midwest, to date.
SOD can kill standing oak trees, which could happen if SOD-positive rhododendrons were planted within about 6 feet of a standing oak. 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.
View a list of those plants (PDF, United States Department of Agriculture).
If you have purchased rhododendrons in April or May 2019 in these communities, call 1-866-NO-EXOTIC (663-9684) or call the local county extension office at 1-888-EXT-INFO (1-888-398-4636) for instructions.
The DNR is destroying all rhododendrons from the source nursery, Park Hill Plants (Oklahoma), and any other host plants that were co-mingled with them. In addition, the DNR is quarantining the sale of four other common SOD host plants (viburnum, azalea, cameilia, and pieris) for further testing to determine if they contain SOD. Testing will determine if other species are infested and require destruction. This is an ongoing investigation, and guidance could change as more information is gathered.
To learn more about SOD, visit the USDA Website.
For more information contact:
Indiana Department of Natural Resources
Division of Entomology and Plant Pathology
402 West Washington Street, Room W290
Indianapolis, IN 46204
- 5/29/2019 - Oak threat in Indiana expands statewide
- 5/22/2019 - DNR finds oak threat in store rhododendrons