Sudden Oak Death Threat

Georgia received more nursery plants potentially infected with sudden oak death than any Eastern state, and a large number of those plants were bought by the public and likely planted around homes across Georgia.

Monrovia Nurseries in California shipped about 28,000 plants to Georgia from January of 2003 to March of 2004 that could have been infected with sudden oak death (SOD), a fungus that has killed tens of thousands of oak trees in 13 California counties and one county in Oregon.

So far, testing has confirmed plants infected with SOD at 13 Georgia nurseries spread across the state from Dalton and Athens in the north to Atlanta and Augusta, and south to Douglas and St. Simons. Those plants were destroyed, but by the time testing was started, approximately 18,000 plants possibly infected with SOD were already gone from the nurseries. So far only about 300 of the plants bought from nurseries that were possibly infected with SOD have been tested. Three of those tests came back positive for sudden oak death, and the infected plants were destroyed.

According to James Johnson, Forest Health Coordinator for the Georgia Forestry Commission, SOD has not been detected on nearby plants or in the landscape where infected nursery plants were found.

“We’re monitoring near the nurseries that received infected plants and near the sites where we got the three positives from homeowners. It’s important for people to know that right now, Georgia does not have sudden oak death,” James said. “We do have nursery plants that were sent here that were infected, but sudden oak death has not been found outside of those plants.”

The Georgia Forestry Commission is trying to educate the public about sudden oak death. They have a brochure that is available by calling 800-GA-TREES.

It is unknown what would happen if SOD spread through the woods of Georgia, but a worst-case scenario would be the widespread death of white and red oaks, trees that are extremely important to wildlife here.

Sudden oak death was first detected in Marin County, Ca. on a tanoak tree in 1995. It has since spread through 13 coastal counties of northern California and in one county of southwest Oregon along the California border. It is thought that the disease prefers wet, cool climates, however the discovery of the fungus on camellia plants at the Monrovia Nursery occurred in Los Angelas County, well away from any area previously infected by SOD.

There is also little information on the life history and characteristics of how sudden oak death is spread, even in California. Researchers believe that infection propagates on the leaves of understory host plants, such as rhododendron and buckeye, causing a rapid build-up of the fungus in the environment, which then can infect oaks.

The Georgia Forestry Commission is asking for help from homeowners who bought the following nursery plants from January 1, 2002 to July 1, 2004: camellia, rhododendron, pieris, viburnum, and syringa. If you bought these plants, watch for symptoms of dieback on the twigs or spots on the leaves. If you notice symptoms of SOD, do not dig the plants up. Instead, contact your local county extension agent.

According to James, the peak time for symptoms of SOD in Georgia will be April and May.

A symptom of sudden oak death on nursery plants is spots and dieback on leaves. If you bought a camellia, rhododendron, pieris, viburnum, or syringa between January 1, 2002 and July 1, 2004, watch for these symptoms and contact your county extension agent if you see them.