Known for their colorful spring flowers and heartiness in cold conditions, rhododendrons are a pretty popular plant in Pennsylvania.
Unfortunately, they’re also the subject of a new warning from the state Department of Agriculture.
In a news release Monday, officials warned that Pennsylvania is among 28 states where retailers received rhododendrons which may have been exposed to a plant pathogen called Phytophthora ramorum.
It causes infectious disease in plants and shrubs including rhododendron, mountain laurel, lilac, viburnum and pieris.
Phytopthera ramorum, also commonly known as ‘Sudden Oak Death,’ was first detected in California in 1995 and is under federal quarantine.
Anyone who has recently purchased a rhododendron is asked to monitor the plants for signs of disease, including leaf spots (also known as leaf blight) and shoot dieback, along with necrosis on the leaf tip. Other rhododendron problems may mimic the disease, but a lab test is needed to confirm the pathogen has infected the plant.
According to SuddenOakDeath.org, not all brown spots on rhododendrons are caused by Phytophthora. Some leaves may be sun scorched and susceptible to blight.
If you suspect rhododendrons you purchased may have the disease, contact your county’s Penn State Extension office or the state Department of Agriculture regional office for instructions on how to send in a sample for testing.