INDIANAPOLIS — More than 70 Walmart stores and 18 Rural King stores in the state have received rhododendron plants infected with Sudden Oak Death, a fungal pathogen that kills oak trees.
According to Indiana Department of Natural Resources, shipments containing infested material were sent to nine other states, as well. The investigation is ongoing.
The pathogen can kill standing oak trees, which could happen if SOD-positive rhododendron were planted within about six feet of a standing oak.
“Basically, you are looking for browning on the leaves,” said Megan Abraham, division director and state entomologist at the Division of Entomology and Plant Pathology.
“This fungal pathogen will make it look almost like it’s been burned, like if you’ve overwatered it. The plant could take on an overall wilted looking appearance.
“This pathogen can infect over 100 different species of plant — not just rhododendron.
“It can hide in over 100 different species and not even show any symptoms, in certain cases.”
The good news, Abraham said, is that the shipment has been tracked to its source.
If your rhododendron is not from a Walmart of Rural King, and you didn’t receive it between February and now, then it’s unlikely your plant suffers from Sudden Oak Death.
It’s important that the disease doesn’t spread to new regions.
“It has done quite a bit of damage to the oak populations on the West Coast,” Abraham said. “They have a slightly different oak population than we have here. But it should have the potential to do the same thing to trees here that it did out there.
“What it would do is essentially wipe out large chunks of our oak forests. Because oak is such a predominant part of our natural resources here in Indiana and the Midwest, that’s why this pathogen is such a dangerous one to have near our forests.”
Workers from the Department of Entomology and Plant Pathology have been visiting stores across Indiana to destroy any stock that has been found infested and quarantine any stock that is symptomatic.
The DNR has destroyed approximately 1,500 infested rhododendron so far and pulled another 1,500 from stores.
The DNR also has ordered these stores to stop selling rhododendron until further notice. Any quarantined material not infected will be released following testing at Purdue University.
If you have purchased rhododendrons from Walmart or Rural King, destroy them, or call 1-866-NO-EXOTIC, or 1-866-663-9684, or the local county extension office at 1-888-EXT-INFO, or 1-888-398-4636, for instructions.