Native to northwestern China, wolfberry (Lycium barbarum) now grows wild throughout most of the United States and Canada. Related to tomatoes and potatoes, wolfberry provides edible shoots when young. Wolfberry hedgerows may be planted to stabilize sandy areas, but in many locations the plant has become an invasive noxious weed. Also called goji, the red berry of this vine is used in Chinese herbal remedies and modern nutritional supplements.
Most recent investigations of the wolfberry's medicinal properties originated in China, where goji fruit has been a part of popular anti-aging tonics since the Ming Dynasty. Herbal remedies often combined goji with chrysanthemum flower and other herbs. Benefits included restoration of failing eyesight in the elderly. Studies conducted at the University of Hong Kong confirm that the berry contains useful levels of zeaxanthin, an important eye nutrient.
Wolfberry bears fruit that is only edible when fully red and ripe. Mild and sweet with a licorice flavor, wolfberry fruits can be eaten fresh or dried and make an interesting tomato-like addition to soups and stews. Young shoots and foliage of the vine resemble cress and peppermint in flavor. Solanaceae plants may have harmful effects; cooking the plants in boiling water for a few minutes reduces the risk.
The wolfberry plant, also called matrimony vine, tolerates a wide range of soils from shifting sand dunes to heavy clay. This tough perennial forms thick hedges with branching individual tendrils from 3 to 18 feet long. Flowering extends from June to late August, with the last berries ripening in October. Though thorny, goji's ornamental and edible qualities make it an attractive choice for a garden border in tough growing conditions. Once established, the vine can be as difficult to control as honeysuckle.
Many producers of herbal tonics and supplements claim goji berries contain extraordinary amounts of vitamins C, E, B and A, as well as an abundance of trace minerals. Actual nutritional value of herbs and fruits depends on preparation and preservation methods as well as on the initial value. No studies prove that goji alone prevents cancer, diabetes or other serious illnesses. Goji adds important nutrients like lycopene and zeaxanthin to the diet, but so do many other common foods. Goji in traditional herbal medicine is considered an important part of treatments rather than a cure-all.
Goji tonics often contain a mixture of juices, including grape, apple and pear puree, as well as an unknown amount of goji juice. Maximum nutritional value comes from the fresh berry rather than processed or dried products. The vitamin C content of dried goji could be accurately estimated by comparing it to a well-tested product: the raisin. Though made from high vitamin C grapes, the vitamin C content listed on a raisin box is zero.