North Carolina’s agricultural landscape is one of the most diverse in the country, and now researchers are exploring a possible new crop with the addition of tea.
They’re working to evaluate tea plants or develop new plants – looking for ones that thrive in colder climates, deliver unique health benefits and serve double duty as both landscape ornamentals and sources for caffeinated beverages.
Ultimately, researchers are exploring the potential of growing tea (Camellia sinensis) and yaupon (Ilex vomitoria) as viable specialty crops for North Carolina farmers. Their work could create exciting possibilities for gardeners and tea drinkers, too.
“Carolina Super Teas” is the name of a research project led by Tom Ranney whose Ph.D. is in horticulture and plant protection. He and his research team in N.C. State University’s Department of Horticultural Science are based at the Mountain Horticultural Crops Research and Extension Center in Mills River.
They are able to explore this possible new specialty crop thanks to funding from the New and Emerging Crops Program. The work falls in line with program’s goals of identifying and developing promising crops that can strengthen North Carolina’s agricultural economy.
The N.C. General Assembly approves funding annually for the program, and the Research Stations Division of the N.C. Department of Agriculture and Consumer Services oversees it. The program has awarded more than $168,000 to Ranney’s team to support research on tea plants and their relatives.
“Teas are big business,” Ranney told attendees at a project presentation. “If you look at 2024, the global value for tea was about, so it is the second most consumed beverage, second only to water globally. So, it is big business and quite significant in different parts of the world.”
That kind of demand creates opportunities, especially if researchers can adapt the plants to new regions and growing systems like those in North Carolina.
Expanding the Tea Plant Family
Ranney leads the Mountain Crop Improvement Lab at N.C. State, where the team has a long history of breeding nursery crops like camellias and hollies. Recently, they’ve extended that work into the world of caffeinated teas, using traditional breeding methods and germplasm collection to explore new possibilities in both the classic tea plant Camellia sinensis and also several species of Ilex, which is the holly genus that includes native yaupon (Ilex vomitoria), yerba mate (Ilex paraguariensis) and guayusa (Ilex guayusa).
“Yaupon holly is the only plant native to North America that produces caffeine, and it’s found natively from Virginia down to Texas, mostly along the Atlantic coast,” Ranney said.
As for Camellias, they have been grown in the Southeast for a long time, mostly as landscape plants, while most tea production worldwide still happens elsewhere. However, growing tea in the Carolinas isn’t completely unheard of. Ranney points to The Pinehurst Tea Company in South Carolina that dates back to the late 1800s. Smaller scale tea production goes back even earlier he said.
“In terms of tea production areas, historically, it has been more in subtropical and tropical areas, certainly in Asia, China, India, some in Turkey and the Middle East, a little bit in Africa and South America. But there have been efforts over the years to try and push tea production into more colder-temperate regions,” Ranney said. “In terms of tea production in the United States, it has an interesting history. Pretty much as soon as Europeans started to settle here, they experimented with growing teas, and it wasn’t until the late 1800s that there were some significant plantations and farms.”
By pushing the boundaries of cold hardiness, the hope is that these plants can be grown more reliably in the Southeast and into Zone 6.
Dual-Purpose Plants for a New Market
The lab is especially focused on developing dual-purpose plants that work as attractive landscape plants and offer potential for tea production. So, they’re working to develop plants with cold hardiness, good branching structure for hedging or mechanized tea harvesting and ornamental traits like variegated foliage or pink flowers. They also plan to identify plants with high levels of metabolites like caffeine and others that contribute to tea quality in their crop improvement. There is an interest in developing some plants with high theacrine content because it may be useful in some teas or other beverage production. Research has found that yaupon holly, in particular, has that compound, which is a cousin of caffeine and offers a stimulating effect like caffeine but without the negative heart rate or blood pressure effects. So, plants with high theacrine could create tea and other products that offer an intriguing angle for the health-conscious consumer.
“Our objectives are actually kind of similar for both the camellia tea and holly tea projects, which are to develop and screen new hybrids for cold hardiness, these related purine alkaloid compounds and also commercial traits for both landscape and tea production,” Ranney said. “If we can have these diverse markets and different sales channels, it makes the crop more valuable. So, we’re very interested in this dual purpose of plants that you can drink and also have potential for nursery and landscape crops.”
Field Trials and Global Collections
John Nix, a research specialist with the crop improvement lab, is leading day-to-day efforts to improve both tea camellias and tea hollies through plant breeding, field trials and field collection. Through partnerships with nurseries like Camellia Forest Nursery and Cam Too Nursery, the team has added elite commercial tea varieties from China and Japan. One such variety is Camellia sinensis ‘Yabukita’ which makes up nearly 75% of the tea in production in Japan. These commercial varieties will be a great benchmark to test against for desirable tea quality, Nix said.
Meanwhile, new breeding lines with enhanced cold hardiness are being selected for both container production and field planting. Nix said they’ve already trialed tea camellias hardy to 0°F, with plans to intercross those with high-quality commercial types.
For Ilex species, much of the focus is on Ilex vomitoria (yaupon). As the only native North American plant known to produce caffeine, it’s been used for centuries by Indigenous peoples in the Southeast.
“There’s sort of a resurgence of interest in yaupon teas. Just seven years ago, the American Yaupon Association was formed to promote the production and development of this as a crop in the southeastern United States, and it’s now found frequently in stores. There are quite a few companies that are producing yaupon tea,” Ranney said.
For example, Asheville Tea Company is developing yaupon blends with ingredients like elderberry or spices.
But not all yaupons are created equal. Initial metabolite screening showed dramatic variation in caffeine content between cultivars. Nix said early testing involved just four yaupon plants that were in the nursery in the early days of the project.
“[We found] more than a 10-fold difference in caffeine. So that’s a lot of variance. And if you were making tea out of a yaupon without looking at this [testing data], you can maybe tell the quality of tea by how you feel drinking it, but you don’t know how good a selection is for tea production without some information like this,” Nix said.
They’ve also tested other purine alkaloids that contribute to the tea quality, particularly theacrine. Some had almost no theacrine, but some cultivars had measurable amounts – important information, Nix said.
To find yaupon selections better suited for colder areas, the team has launched a germplasm acquisition campaign across the Southeast. With permits in hand, Nix traveled to the mountains of west central Arkansas last fall, seeking and collecting wild Ilex vomitoria populations at the edge of the species’ range. Considering that yaupon holly primarily occurs throughout the coastal plain of the southeast, Nix found it interesting that plants occur so far inland within the Arkansas mountains. Cuttings and seed from those plants will be grown and trialed to contribute to the crop improvement effort.
“We were able to get 31 clonal selections from this trip, and that’s from around 11 different sites. And for each of those 11 sites, we were able to get a seed lot to try and hopefully capture some more diversity,” Nix said.
All of those are now being propagated and screened for rooting, form and tea quality. A similar expedition is planned for southeastern Virginia – again targeting populations near the cooler edge of yaupon’s natural distribution.
The project includes collaborators beyond N.C State, too. Dr. Ryan Yates at the University of Mississippi is helping with metabolite analysis, using advanced chromatography to profile each plant’s purine alkaloid content. Carlos Iglesias, a global plant expert, is contributing expertise on yerba mate and helping import seed lots from Uruguay and Brazil. Mark Weathington, director of N.C. State’s J.C. Raulston Arboretum, has also collected germplasm in South America.
Together, the team is assembling a unique and diverse foundation for the future of caffeinated crop breeding in North Carolina.
The Road Ahead
Ranney and Nix said they’ll continue evaluating their wild and cultivated collection of plants for traits that matter to growers, processors and consumers. The first field plantings of tea hollies and interspecific hybrids are planned for spring 2026, with ongoing trials to assess cold tolerance, tea quality and production traits.
The work aims to build new crops from the ground up, not just look for one perfect tea plant. The researchers hope to build a palette of plants that can serve many different needs, from commercial farming to home gardening to the nursery trade.
[button link=”https://mountainhort.ces.ncsu.edu/2025/05/2025-mtn-hort-field-day/” color=”red”] For anyone interested in seeing the project up close, the team invites the public to the upcoming Field Day at the Mountain Horticultural Crops Research and Extension Center in Mills River on Thursday, Aug. 14. Click this box for the link.[/button]