Sweet Potato Greens Offer Nutritious, Climate-Resilient Food Source

Sweet potato greens (SPG) could offer consumers a nutritious alternative to traditional leafy vegetables while helping farmers produce two food products from a single crop. Lincoln University of Missouri (LU) researchers Waana Kaluwasha and Safiullah Pathan recently examined the nutritional value of young sweet potato leaves and stems grown under different farming systems and soil-management practices.

Kaluwasha and Pathan noted that sweet potato greens, which consist of young leaves and stems, commonly appear in diets throughout parts of Asia and Africa where farmers grow sweet potatoes. Rich in protein, fiber, minerals, essential amino acids and health-promoting bioactive compounds, the greens offer a nutritious alternative to familiar leafy vegetables such as spinach. However, consumers and producers in the United States have yet to widely embrace them.

"Increasing interest in the nutritional and health benefits of food has prompted researchers to explore non-traditional leafy greens such as SPG," Pathan said. "A few studies have been done in the United States; however, further research is needed."

To expand existing knowledge, the researchers examined the young leaves and stems of three sweet potato varieties: Covington, Murasaki and White Bonita. They compared plants cultivated through conventional and organic farming systems, both with and without a mustard cover crop.

The study found conventionally grown greens contained more protein, fiber, fat, minerals and essential amino acids, while organic greens contained more carbohydrates and copper. Despite statistically significant differences, overall nutritional variation remained minimal.

Cover-crop use influenced the greens' nutritional content less than the overall farming system. Plants grown with a mustard cover crop showed modest increases in protein, iron, zinc and several essential amino acids. Conventional production combined with a cover crop produced the highest total essential amino acid content among all treatment combinations.

Flowers blooming on a Murasaki sweet potato plant, one of three varieties examined in a Lincoln University study on the nutritional value of sweet potato greens.

Nutrient levels showed little variation across farming and soil-management practices, while the three sweet potato varieties showed similar nutritional values. Such consistency suggests sweet potato greens retain important nutritional qualities under a range of growing conditions and gives farmers flexibility to select varieties based on yield, disease resistance, root characteristics or other production goals.

"These varieties were selected for their unique storage root characteristics and differences in susceptibility to postharvest diseases, but nutritional differences among the three were insignificant," the scientists said. "This means farmers can choose any variety for SPG production, but they may look into higher-yielding varieties if also growing sweet potatoes for storage roots."

Beyond their nutrition, sweet potato greens could help farmers expand the usefulness and market potential of an existing crop. Producers can harvest young shoots as leafy vegetables early in the growing season, followed by storage roots later. The dual-purpose approach allows farmers to produce multiple food products from the same plants.

Sweet potatoes also tolerate heat and drought, making their greens a promising climate-resilient food source. Their adaptability and nutritional content could support affordable food production while strengthening nutritional security in communities facing environmental and economic challenges.

"A multi-year, multi-location study across both research field and small-farmer fields, in addition to awareness initiatives, will help popularize SPG as an alternative leafy green vegetable," the researchers commented.

Before drawing broader conclusions, the researchers recommend studying additional varieties across more locations and growing environments. Multi-year research on university plots and small farms, paired with public education, could clarify how local conditions affect nutritional value and production while encouraging farmers, food professionals and consumers to consider sweet potato greens. By providing nutritious shoots early in the season and storage roots later, sweet potatoes offer growers a flexible crop with the potential to strengthen local food systems and expand access to nutritious leafy vegetables.