MOUTH OF WILSON — Birds and bird watchers love it. Park rangers and farmers could live without it.
Autumn olive is considered one of the most invasive woody species in Southwest Virginia parks and pastures. But because it has not been placed on the state’s list of regulated plants, it’s still sold by nurseries and planted by unsuspecting landowners.
These days, it doesn’t even need human help to spread. Once the attractive shrub gets a foothold, it moves aggressively. Birds eat the many pounds of red berries it produces annually and then drop the seeds in every direction. Once a plant establishes itself, its root system sprouts new bushes.
Scattered among the wild highbush blueberries and red spruce trees at 5,000 feet in Grayson Highlands State Park, autumn olive bushes shoot up and threaten even this sensitive alpine ecosystem, where few other invasive plants survive.
Jordon Blevins of the Virginia Department of Conservation and Recreation attacks them one at a time with a spray bottle.
Braving ticks and the spiky outer branches of the autumn olive on a recent Friday afternoon, he used triclopyr, a brush-killing herbicide, to bathe the bark on each main branch near the ground. It’s the only effective weapon he has.
As a DCR resource specialist, Blevins tackles many invasive plants in Southwest Virginia’s state parks, including Grayson Highlands, Natural Tunnel, Wilderness Road, New River Trail and Hungry Mother.
Autumn olive is an especially wily opponent. Burning won’t kill the shrub, which can grow 15 to 20 feet tall. If you cut it down, it will re-sprout from its roots. Even if there were labor and time enough to pull its roots out of the ground, new seeds would sprout the following year.
“Keep them at manageable levels is about all we can do,” Blevins said. “They’re just so hardy.”
In fact, autumn olive can go where few other invasive plants are found.
Looking out at the misty-blue views that roll away in every direction, visitors won’t see other common invasives. Privet, Japanese stiltgrass and about a dozen other troublesome imports won’t grow at this elevation, Blevins said. Only autumn olive does.
Making itself at home
Jacob Barney, a plant ecologist at Virginia Tech, has studied invasive species for 20 years and in recent seasons has worked on the problem of autumn olive.
Introduced intentionally to the U.S. from Asia in the 1830s as an ornamental plant, autumn olive became popular in the mid-20th century to prevent erosion on mining reclamation sites, road cuts and the like and on farms and in back yards to draw wildlife. Now it’s infested much of the eastern United States.
“From those initial plantings, it spread aggressively,” Barney said. “It’s particularly successful because it is able to fix atmospheric nitrogen through root nodules. That lets it grow in places where it’s very nutrient poor.”
Besides herbicides, deep shade appears to be its only enemy, according to Blevins. While the autumn olive will sprout on wooded edges, heavily wooded parks have little trouble with it, he said.
But on open ground, it’s crowding out native flora and making it harder to restore ecosystems.
Autumn Olive tends to “spread into open fields, disturbed areas and in the undergrowth of the forest, so it is basically a threat to almost all native plants in [Virginia],” according to John Magee, horticulture chairman for the Virginia Native Plant Society.
“Once it establishes itself in an area, it works to change the soil chemistry favoring other non-native species and making it difficult to re-establish natives once an area has been cleared of Autumn Olive,” Magee wrote in an email.
Not everyone recognizes it as an enemy, however.
“There are ... some bird lovers who still encourage planting the plants to improve habitat for birds,” Magee wrote. “Unfortunately, the plant does the exact opposite, as studies have shown that when birds use the plant for nesting, they tend to nest lower to the ground leaving themselves vulnerable to higher predation.”
Despite the damage it can do, autumn olive is still legal to sell and to plant across the commonwealth because it is not included on the state’s Noxious Weeds List.
Under state law, importation, movement or sale of plants included on the list requires a permit and may be barred. But for years autumn olive did not qualify because it was planted widely by state government entities and private landowners.
The “initial list was developed when only plants that were ‘not widely disseminated’ in Virginia could be listed,” said Elaine Lidholm, spokeswoman for the Virginia Department of Agriculture and Consumer Services.
The law recently changed.
“The ‘not widely disseminated’ restriction was removed in 2016 when the General Assembly amended the Noxious Weeds Law,” Lidholm wrote in an email. “Since that restriction was removed, our office of Plant Industry Services has been working to develop a process for evaluating plants for adding to the list.”
Any new plants nominated for listing would have to “go through the evaluation process and then be approved,” Lidholm wrote.
It’s unknown if autumn olive will be considered for listing in the near future.
Uncurable and costly
Autumn olive is also problematic on farms in the western part of Virginia, where it can quickly gobble up pastureland, said Andrew Smith, a lobbyist for the Virginia Farm Bureau.
Years ago, Smith said, his mother got some autumn olive seedlings for free and planted them on her land. At first, “they made a nice hedgerow; then they began to spread like wildfire,” he said.
“It’s not an ugly plant — unless you’re a farmer,” Smith said. Controlling the invasive bush can be a major expense, he added.
The cost to the U.S. economy of all invasive species is “estimated at $120 billion a year, with over 100 million acres (an area roughly the size of California) suffering from invasive plant infestations,” according to the Nature Conservancy, a national nonprofit environmental organization.
It costs taxpayers, too. The commonwealth’s Department of Conservation and Recreation, which oversees about 70,000 acres of state park land and 57,000 acres of natural heritage land, must battle autumn olive and a number of other invasives.
“It is a problem we are very much aware of, that we dedicate resources to,” DCR spokesman Jim Meisner Jr. said.
The agency spends $86,000 annually on invasive plants and insects. Nine staff members spend part of their work hours on this issue, and hundreds of volunteers provide labor to control the plants. Still, it’s a partial solution.
“Our goal is mitigation and management,” Meisner said. “Eradication is just not possible for anyone, anywhere.”
Blevins said the best advice is to kill autumn olive when it’s just getting started, and to regularly monitor your property for it.
For a list of bird-friendly plants to grow instead of autumn olive, visit https://goo.gl/j4duTo.
For information on how to manage autumn olive, visit https://goo.gl/6kBiW5.