The Poinsettia: URI Students Learn the Science Behind Growing a $250 Million Holiday Crop

Photo, top: The poinsettia’s vibrant color and distinctive blooms make it one of the most iconic ornamental plants in the United States; managing its light, temperature, nutrition, and timing gives students essential skills for careers in nurseries and controlled-environment agriculture.

URI students are gaining firsthand experience growing poinsettias, one of the most economically important holiday crops

The poinsettia’s vibrant color and distinctive blooms make it one of the most iconic ornamental plants in the United States. According to available data, more than 70 million poinsettias are sold nationwide each year, contributing $250 million to the national economy. At the University of Rhode Island, students are learning to grow this important crop—one that is surprisingly complex to manage—in Professor Camilo Villouta’s “Horticultural Plant Production” course.

Built around managing a real crop in real time, the course responds to industry demands. “We keep hearing from growers that they need students who can walk into a greenhouse or nursery knowing how production works with schedules, environmental control, crop quality, and timelines, not just theory from a textbook,” says Villouta, who is an assistant professor of controlled environment agriculture in URI’s Department of Plant Sciences and Entomology.

Poinsettias are an ideal teaching crop because of their fixed holiday production schedule. “They need to look perfect in a narrow window,” Villouta says, which helps students understand real-world production pressures. Students learn to manipulate light, temperature, nutrition, and pinching techniques to create the desired shape. Weekly recordkeeping on plant height, pH, and electrical conductivity mirrors industry standards, and students synthesize their observations into detailed crop management reports.

“Students have to bring together physiology, nutrition, pest management, ecophysiology, and basic economics to make decisions,” Villouta says. “All of that complexity translates into a lot of learning value for them.” The URI greenhouse, located just steps from their classroom, is central to the “learn by doing” experience. “The greenhouse essentially functions as our lab,” Villouta explains. “Students can walk out, look at their plants, and apply what we just discussed.”

Plant production is “both a science and a craft,” Villouta adds, one that requires daily attention, observation, and informed decision-making. Even crop problems are treated as research opportunities as students learn to diagnose issues and adjust their strategies. “When something goes wrong—maybe plants are stretching or color isn’t quite right—they now have tools to troubleshoot: adjust nitrogen, rethink temperature, look at light levels,” he says. “They’re building the ability to solve real-world problems in a greenhouse or nursery.”

Watching students gain confidence is the most rewarding part of teaching the course. “By the end, they’re not just guessing—they have informed opinions.”

Poinsettias are the focus, but the lessons are translatable. The course is part of a broader effort to connect students with meaningful careers. Real-world relevance is woven throughout the semester as guest speakers share firsthand experience from commercial operations and field trips expose students to greenhouse production in the region.

“This isn’t just an academic exercise,” Villouta says. “There’s a whole industry that needs people who can grow the food we eat and the ornamental plants that make our homes and public spaces beautiful.”

He encourages more students—even those who don’t see themselves as “plant people”—to take the course and experience the challenge of managing a living crop. “It changes the way you look at a poinsettia on a shelf or a head of lettuce in a store when you understand all the logistics, decisions, and care that go into producing it,” he says.

Villouta also credits the success of the course to the people around him. “I’m grateful to our greenhouse staff and local growers,” he adds. “Their support and input are key to making this course practical and grounded in reality. The class works because it’s connected to a real community of people who care about plants and about training the next generation.”

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This story was written by Anna Gray in the College of the Environment and Life Sciences.