Scientists at Mississippi State University’s Forest and Wildlife Research Centre are studying some of the most popular tree species used as Christmas trees, which have long been overlooked for forestry programs.
“Christmas trees are considered a gray area in the forestry industry. Is it horticulture? Is it landscaping? Or is it forestry?” according to Joshua Granger, a Forestry Associate Professor at Mississippi State. “When I came to MSU, we didn’t have any research with these trees, but I’ve begun working with the Southern Christmas Tree Association to develop some studies to help our growers out.”
The work comes at a pivotal moment for Mississippi’s proud history in Christmas tree farms. Once a major producer, the state grew more than 330,000 Christmas trees at its peak in the mid‑1980s. And whilst the industry has contracted since, 30 farms still operate across the state, supplying thousands of trees each year and increasingly pairing sales with agritourism. As older growers retire and younger farmers enter the field, demand for updated research and disease‑resistant varieties has intensified.
Last year, Granger began research for a partnership between MSU and Shady Pond Tree Farm in St. Tammany Parish, Louisiana. Former owner Clark Gernon had discovered a novel variety of Leyland cypress, a popular, fast‑growing species, on his farm. The single tree was unique in its apparent resistance to Passalora sequoia—a fast‑spreading foliar pathogen attacking his other trees.
“This pathogen attacks the foliage either top-down, bottom-up, or inside-out until it all turns brown and dies,” he said. “Because the American market likes a cone-shaped, dense tree, farmers have to shear the trees so they grow denser, and that actually helps the pathogen do more damage.”
Working with Assistant Professor Ashley Schulz and forestry undergraduates, Granger has been rooting plant material from the christened Leighton Green Gernon trees in the department’s greenhouse. The trees will remain there for a year before being transplanted outdoors, where they will be grown and propagated long‑term.
“It was Mr Gernon’s dream to have researchers study the tree, trial it, and qualify it as a unique cultivar or species. He passed away last Christmas Eve, but we are carrying out his wish through our work on campus,” he said.
In a separate project, Granger is exploring additional species for their potential as Christmas trees. “Leyland cypress trees are planted across Mississippi and much of the South as an ornamental, in addition to their cultivation for Christmas tree farms,” he said. “The Leighton Green Gernon trees grow well, but their needles have a white-blue tone, which might be a more niche market. Most people want a dark-green tree.”
The long‑term study mirrors the commercial process: establishing trees in a nursery, growing them to about six feet, and shearing them into the dense cone shape consumers expect. Species under evaluation include spruce pine, Atlantic white cedar, Arizona cypress, and Leyland cypress hybrids. Once the trees mature, the team will test consumer preferences and assess how well each species performs indoors over a month or more.
Granger is also launching a collaboration with Joby Czarnecki, an associate research professor in MSU’s Department of Plant and Soil Sciences and the Geosystems Research Institute. Together, they are deploying scanning technology in Leyland cypress stands to detect early signs of Passalora sequoia.
“Right now, growers are using a standard spraying protocol, regardless of whether the tree needs it or not,” Granger said. “If we can identify the extent of the damage, we can provide better guidelines that will save growers time and money.”
At MSU’s Hiram D. Palmertree North Mississippi Research and Extension Center in Verona, scientists have just completed a three‑year study requested by the Southern Christmas Tree Association and supported by a specialty crop block grant from the Mississippi Department of Agriculture and Commerce. Jeff Wilson, an associate professor of ornamental horticulture with the MSU Extension Service, investigated nitrogen application rates on three species commonly grown on Southern Christmas tree farms.
“Before Dr. Granger and I started this work, there had not been any research on Christmas trees in Mississippi since the late ’70s or early ’80s, but there is a real need for the research today,” he said. “We have growers who have sold Christmas trees for 50 years, and although the farming population is aging, we’re also seeing younger people start up new farms as a side business, selling trees and branching out into agritourism.”
The study will conclude this winter as Wilson and his team harvest and sell the trees, but he hopes it marks the beginning of a broader research effort. “This was just one small nitrogen study, but there’s a long list of different studies we could do that would benefit growers across the state, helping them manage their trees more efficiently and increase their profits,” he said.
