Sudden Oak Death (SOD) Quarantine
I'm cutting and pasting an article that appeared in the Indianapolis Star on 3/31/04. It's old news around here (IN), but some of you may not know about it...
Plant quarantine aims to protect oaks By Tammy Webber
March 31, 2004
Gardeners looking for rose bushes and dozens of other plants temporarily might have a hard time finding them if their nursery relies on California stock.
Indiana officials on Tuesday imposed an emergency quarantine on 30 plant species from California, saying they hope to spare the state's oak trees from sudden oak death, a disease caused by a funguslike pathogen that the plants might carry.
Tens of thousands of California oak trees have been killed by the pathogen, Phytophthora ramorum, which appeared in the mid-1990s. It recently was discovered in nursery stock there, prompting several states to impose similar quarantines.
"We want to get the word out to (retailers and nurseries) and let the public know that we're doing what we can to see that this doesn't get introduced here," Indiana Department of Natural Resources spokesman Russ Grunden said. "When they go to the garden shop in the next few weeks, they can be as sure as anybody can that . . . they're not going to take it home with them."
Indiana nurseries that already have California plants in stock must quarantine them until they are inspected by the DNR, State Entomologist Robert D. Waltz said. The agency has eight inspectors to visit any nursery or store that indicates it has California plants. No new plants may be brought in unless California officials have certified that the supplying nursery is free of the pathogen.
Gordon Hobbs, president of C.M. Hobbs & Sons nursery, said many local suppliers get the bulk of their plants from states such as Tennessee, Ohio, Oregon and Michigan. California, however, accounts for about half of the plants in the nation's nursery trade, he said.
Waltz said he hopes the quarantine was enacted before most of the spring shipments arrived.
But it came too late to prevent a shipment of California roses to Allisonville Nursery, inventory manager Mary Gorrell said. Many of its rose bushes are from California, though only a few of its other plants are from that state, she said.
Gorrell said she supports the quarantine even though it could cost the nursery money.
"A huge oak tree is invaluable; it's priceless," she said. "I think we need to protect our large, mature trees."
About half of all Indiana trees over 20 inches in diameter are oak, said Bill Bull, assistant state forester in the DNR forestry division. Indiana has 4.5 million acres of forestland, including about 1.8 million acres of oak and hickory-type trees, he said.
Although Indiana is considered to be at moderate risk for the disease, Bull said the impact would not be light if it got a foothold here. Lumber is the fifth-largest industry in the state, "and Indiana produces some of the finest hardwoods in the world." Forestlands also are used for recreation, provide wildlife habitat and help protect water quality, he said.
DNR officials will fax and mail letters about the quarantine to an estimated 4,000 nurseries and other businesses that sell plants. About 600 of those are known to carry California plants, Grunden said. The Indiana Nursery and Landscape Association also will inform its members, Executive Director Donna Sheets said.
Sudden oak death has been found in 12 California counties and a small area in Oregon, said Dave Rizzo, a professor and researcher at the University of California at Davis. Rizzo was one of two researchers who first identified the pathogen in 2000.
He said nobody knows where the pathogen originated, but it also appeared suddenly in both California and Western Europe in the mid-1990s.
The organism encircles oak trees and literally strangles them. The pathogen doesn't spread from oak to oak but is spread from host plants -- such as rhododendrons and maple trees, he said.
Although Rizzo understands why Indiana and several other states imposed quarantines, he's not certain how long they will stem the spread of the disease, partly because more than 50 plants and trees may carry the disease and transmit it to oaks.
"I'm not sure how effective (quarantines) will be," he said. "It's a matter of time before something gets out."