If you’ve heard of goji berry (or wolfberry), then you’ve probably heard the claims that the Chinese native is a “super food.” While some purveyors are less than honest, studies throughout the United States and China confirm the health benefits of the little berry.
For growers, the increasing popularity of the goji berry offers the opportunity to enter a market that has expanded beyond ethnic specialty and into the realm of health food. Unlike many fruits, which grow best from cuttings, goji seeds can be saved for future use with little risk of surprises in the field. As researchers begin modifying the seeds, or creating hybrids from the seven varieties of Chinese goji, this may change. According to USDA data, only four varieties of Chinese wolfberry currently grow in North America.
Varieties and basic information
• Lycium barbarum Linnaeus (Ningxia gou qi) is the most widely propagated form of goji in China. Practitioners of traditional Chinese medicine consider Lycium barbarum, which grows in the Ningxia province, superior to other goji and rely solely on this species. The shrubs grow from 0.8 to 2 meters tall and have thorny, hairless branches. Berry color and seed production differ between the two varieties of Lycium barbarum.
Lycium barbarum var. auranticarpum (huang guo gou qi) produces orange-yellow berries from 4 to 8 mm in diameter, with each berry containing between four and eight seeds. Lycium barbarum var. barbarum (Ningxia gou qi), and its subvarieties Lycium halimifolium Miller; L. lanceolatum Veillard; L. turbinatum Veillard and L. vulgare Dunal, produce red berries ranging from 6 to 10 mm in diameter. Each berry contains more than 15 seeds. This variety grows on slopes, near fields and houses or by ditches. It is widely cultivated for medicine throughout China, especially in Ningxia and Tianjin Shi and has been cultivated and naturalized in Asia and in Europe.
• Lycium chinense (gou qi). The varieties of Lycium chinense differ greatly in appearance and grow wild on slopes, wastelands, saline places and in residential areas throughout China and other parts of Asia. Shrubs may be erect or sprawling and range from 0.5 to 1 or 2 meters tall. The leaf blades may be short and fat or long and spear-like, while the red berries may be ovoid or oblong, ranging from 0.7 to 1.5 cm by 5 to 8 mm. Cultivated Lycium chinense bears larger fruits. Lycium chinense berries contain numerous yellow seeds.
The many subvarieties of Lycium chinense var. chinense are cultivated in China as a medicinal plant or vegetable. People use the fruits as a tonic, and the root bark for relieving cough and reducing fever. They eat the young leaves as a vegetable and use the seed oil as a lubricant and for cooking. The Chinese also grow this species to control erosion.
Lycium chinense var. potaninii (Pojarkova bei fang gou qi) bears thin leaves and oblong berries ranging in size from 2 to 2.5 mm by 1 cm. This variety is occasionally cultivated, and grows wild on sunny slopes and in ditches.
Health and marketing
A report by doctors at the University of Hong Kong states that although Lycium barbarum has been used for centuries to nourish the liver (thereby improving eyesight) and reduce the signs of aging, its beneficial effects to the human body require further study with modern technology to unravel its therapeutic effects at the biochemical level. The valuable components of L. barbarum are not limited to its colored components containing zeaxanthin and carotene, but include polysaccharides and various vitamins.
Results of a recently published study conducted at Ningbo University School of Medicine in Ningbo, China, suggest that Lycium barbarum may be an anti-cancer agent. At the Strang Cancer Prevention Center in New York City, researchers discovered that it inhibits growth of estrogen receptor-positive human breast cancer cells. A study at Fu Jen University, in Taipei, confirmed that the fruit of Lycium barbarum Linnaeus contains carotenoids, flavonoids and polysaccharides that may prevent chronic diseases, such as age-related macular degeneration.
Researchers at the Laboratory of Neurodegenerative Diseases at the University of Hong Kong recently demonstrated the neuroprotective effects of Lycium barbarum. “We have accumulated scientific evidence for its anti-aging effects that should be highlighted for modern preventive medicine,” writes R.C. Chang. “We hope that new findings for L. barbarum will pave a new avenue for the use of Chinese medicine in modern evidence-based medicine.”
Finally, an analysis of the leaves of cultivated Lycium barbarum L. conducted at the Chinese Academy of Sciences in Wuhan, China, identified the predominance of the flavonoid rutin in goji leaves. Both wild and cultivated goji fruits contain about 6 percent of the rutin content in the leaves. Researchers concluded that cultivated Lycium barbarum leaves are a suitable source for medicine and functional tea.
Chris Kilham (aka. The Medicine Hunter of Fox News fame) visited the Ningxia province in 2009 to investigate goji. This part of China along the southern border of Mongolia is the primary growing and processing area for goji in the world. Kilham, an ethnobotanist and professor at the University of Massachusetts, has also studied goji. He says that contrary to some claims, goji is not a cure-all. “What it is, is a very healthy berry that’s super rich in antioxidants, especially zeaxanthin, which is very good for the eyes.”
Lycium barbarum bushes are prolific, but the berries are delicate and require care when picking. Kilham observed that Ningxia’s farmers harvest the goji crop entirely by hand.
Instructions for growing goji from seed are available at www.gojitrees.com/apps/links/. Goji trees are available at www.gojitrees.com, and via Henry Fields catalog, SaskGoji, as well as through special agreement with Wolfberry Agrodevco. Wolfberry Agrodevco is currently marketing production contracts for orchard development. Terry Switenky, owner of Wolfberry Agrodevco, intends to develop new and existing varieties of wolfberry for use in production of food and beverage products.
“We have been developing wolfberry in Saskatchewan since 1998 through a process of selection on varieties that we initially acquired via import,” Switenky says. After disposing of approximately 100,000 plants and varieties due to poor or inappropriate growth, Switenky reports that Agrodevco’s “Sask wolfberry,” has extreme cold and heat tolerance and high yield.
Henry Fields sells potted goji plants for transplant into fields. Their 2010 offerings are open-pollinated from a mother plant with an unknown origin. The company was unable to provide the cultivar name.
Switenky cautions growers to be careful when purchasing goji trees or seeds from online sources. Some varieties are suitable as ornamental plants only. Other varieties can take years to produce fruit. Switenky has also found some organic certifications to be bogus. However, one can verify an organic certificate number with the USDA.
Switenky believes goji is a prime diversification crop for farmers interested in new rotations and markets. “We are selecting several thousand acres over North America to fill a market only serviced through import at this time,” he explains. Growers capable of 1,000-tree lots or larger may apply to be part of Wolfberry Agrodevco’s project. Research is ongoing to establish very early fruiting and maintain acceptable yield. Agrodevco is also conducting seed research and utilizing cuttings to find high oil content. In addition, the company is working to develop a variety of goji that will produce leaves suitable for making tea. Switenky expects the tea variety to be available in five to six years.
The author is a freelance writer based in Massachusetts and a monthly contributor to Growing.