​ Georgia’s forestland is known for its beauty and diversity, and one of the most fun ways to enjoy it is from the seat of a rugged utility vehicle. From that vantage point, one can check up on flourishing seedlings, meander through swishing food plots, or… come to a dead stop. And few obstacles bring outings to a halt more quickly than a thick patch of the invasive species trifoliate orange.

“It’s everywhere,” said landowner Gray McWhirter. “Worse than privet, and it prevents full use of the land.” McWhirter and Georgia Forestry Commission (GFC) Management Forester Jeff Kastle have been battling the thick and thorny masses on McWhirter’s 162-acre Morgan County property for some time. Last August, they employed a forestry mulcher to grind down a sizable patch of it in a hardwood bottom, as it had reappeared after a previous herbicide treatment.

The following April, an inspection showed a smattering of tenacious sprouts had taken hold once again. “Trifoliate orange thorns can flatten tractor tires,” said Kastle, “and it’s hard to get a skid steer in here. It’s got a big root ball, so that’s slow work.”
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Kastle added that this area’s prior use for dairy farming has made the situation worse. The plant bears orange fruit that cows enjoy and birds spread. The resulting thickets are as formidable as a prison wall, or worse. He said hunters have been known to retrieve fallen deer from these patches and emerge with thorn slashes that go deep and draw blood — some requiring stitches!

​“Yard by yard, inch by inch, we take out a chunk of it every year,” said McWhirter. “Gotta take it in small bites and we get about five acres treated every two years.”

Beware the ‘Dirty Dozen’
Trifoliate orange, also known as “hardy orange,” is just one of the invasive plant species that is plaguing Georgia landowners.

In fact, there are 12 others that have earned a ranking on the GFC’s “Dirty Dozen” list of plants wreaking
havoc across the state. (See accompanying table.) Trifoliate orange and Callery pear have recently battled for the 12th spot on the list, indicating there are actually at least 13 troublesome species causing concern. Each species listed has its own distinct characteristics and treatment formulas, so assistance from the GFC Forest Management Team has proven
to be a valuable resource for landowners.

As a group, these invasive species have caused untold amounts of damage to the forests in Georgia. Quantifying the impact is, however, complicated. Acres not used due to infestations? Income not realized because of harvesting hardships? ​Revenue lost to treatment efforts?

A number of strategies and partnerships are being utilized by the GFC to help mitigate the spread of these unwelcome plants, beginning with their point of entry into Georgia.

United States Customs and Border Protection Agriculture Specialists are on the front line at ports of entry, including
Savannah, GA. Specialists check containers, shipments, vessels and equipment for smuggled agricultural products or packaging materials that might contain invasive species that could harm American agriculture and the environment.

“We look for anything that is out of place, looks odd or is moving,” said Milton King, U.S. Customs and Border Protection Supervisor Agriculture Specialist at Savannah Seaport. “The most common regulated plant materials found are federal noxious weeds, hitch-hiking insect and wood-boring pests, prohibited plants and prohibited animal products.”

GFC Forest Health Specialist Chris Barnes calls the Savannah and southeastern area of the state “the Bermuda ​Triangle of invasive species.” He works to foster good relations with port contacts and pays special attention to the
transportation corridors and destination warehouses.

“I visit as many warehouses as I can and bring brochures to help folks understand what we’re looking for,” Barnes said. “At first they were a little unsure, but they realize now we have a common interest; we’re trying to protect what’s
here. Now they call me when they spot something unusual.”

The Battle Plan Is Mapped
Partnerships and teamwork are crucial to the fight against species that disrupt the forest ecosystem. The GFC is a member of the Georgia Invasive Species Task Force, which meets quarterly to discuss the status of invasive species activity around the state. The group also includes members from the Georgia Department of Natural Resources, the University of Georgia and the Georgia Department of Agriculture.

“It’s important that we stay abreast of everything our members are discovering and working on,” said GFC Forest Health Coordinator Lynne Womack.

“The more eyes we have on the issues and the more outreach we can accomplish, the better success we’ll have in combating these species. We know communication with Georgia citizens can make a real difference.”

Ryan Phillips coordinates the GFC’s Invasive Plant Cost-share Program (IPCP), which is funded by the U.S. Forest Service. There are currently five invasive plants on the program’s target list for which payment can be granted for
control: privet, Japanese climbing fern, Chinese tallowtree, Chinaberry and Callery pear.

“We never run out of people who want help through this cost-share program,” Phillips said. “The number of applications, funding requests and acreage amounts has risen significantly through the years.” Private, non-industrial landowners who own at least 10 acres of forested ​land and can provide a practice area of at least three acres are eligible to participate.

Womack said between 2011 and 2021, the GFC has helped 389 landowners control invasives on 13,188 acres for a cost
of approximately $725,340.

One invasive getting a lot of attention is Callery pear, a cultivar of Bradford pear. For many years the trees were sterile — not producing fruit. But in the 2000s, trees began to cross-pollinate and produce abundant amounts of fruit that were spread by birds. More and more urban landscapes are suffering now because of the trees’ undesirable qualities, including weak structure.

“We always recommend native trees,” said GFC Sustainable Community Forestry Specialist Seth Hawkins. “It’s an educational issue in that people have to stop buying them and nurseries have to stop selling them.”

Another readily available invasive is English ivy, which is popular as a ground cover.

“It spreads through root rhizomes and once it goes vertical, it starts giving out seeds,” said Hawkins. “That’s dangerous because a tree wrapped in English ivy is susceptible to wind shear and hides defects.”

While some invasive species can be visually appealing, such as mimosa, wisteria and even kudzu, trained eyes
can be a big help in removing them to save native environments.

The GFC’s Forest Health Team is available to assist all Georgians with the identification and plans for removal of
these undesirables. The GFC website at GaTrees.org contains in-depth materials on all invasive plants and pests
affecting Georgia’s forestland. ■