Goji (also known as Goji berry, Tibetan or Himalayan Goji berry, Chinese wolfberry, etc.) has become a very popular subject on U.S. and Canada functional food products markets recently.  People have claimed it to be a cure for many diseases including cancer and other chronic and degenerative diseases.

Species Info

The entire genus Lycium is known as "wolfberry".  The common name "Chinese wolfberry" may be applied to several different species of Lycium native to China.  Lycium species are deciduous woody perennial plants, growing 1 to 3 m high.  Both L. chinense and L. barbarum species produce a bright red, oblong berry 1 to 2 cm long, each containing 10 to 30 tiny yellow seeds (about 2.5 mm).  It grows as a thick bush with vines.

Uses

In fact, L. barbarum (synonym L. halimifolium Miller) is grown as a common medicine crop in the north of China, while L. chinense is more like as a leaf vegetable crop in the south.  However, both species, as well as others, are used in Chinese traditional medicine and daily diet, often interchangeably.

The berries are bright red in colour and sweet in taste.  Both fruit and bark have been playing important roles in Chinese traditional medicine, where they are believed to enhance immune system function, improve eyesight, protect the liver, and improve circulation.  Fruits can be eaten raw, consumed as juice or wine, brewed into tea or stew soup, or prepared as powder.  

Other commercial applications include juice concentrate, dried berries, berry pieces in granola bars, and skin care products and essential oils made from seed oils (similar as grape seed oil).

Currently in the global functional food industry, there is a rapidly growing recognition of wolfberries for their nutrient richness and antioxidant qualities.  Wolfberry was reported to contain abundant phenolic chemicals, including water-soluble (i.e. hydrophillic) antioxidants (e.g. polyphenols), and lipid-soluble (i.e. lipophilic) antioxidants (e.g. carotenoids).

The combination of these phytochemicals and other micronutrients make wolfberry remarkable nutritional quality.  In laboratory and preliminary human research to date, wolfberries have shown to have potential benefits against cardiovascular and inflammatory diseases, some forms of cancer, diabetes, premature aging, memory deficits, vision degeneration and lung disorders, among other diseases of oxidative stress.

Cultural Conditions

Wolfberry plants are easy to grow once they are established.  They can grown in almost any type of soil, but they tend to grow better in a well drained soil of a fairly alkaline quality (pH 7.8 to 8.2).  Plants have an extensive and deep root system, so that they are very drought tolerant once established. Wolfberry plants prefer full sun to partial shade, but plant them in full sun for the best fruit production.  The plants will not do well in a wet damp condition.  however, adequate moisture should be maintained during both blooming and fruiting, in order to produce best fruits.

First fertilizing is usually done by early spring (before new leaves emergence), and one more application during blooming and fruiting.  When organic manure is being applied, it should be fully fermented without insects' egg or larvae.  Wolfberry plants are relatively resistant to pests.  While chemical spray may seem necessary if fungi, bacteria or aphids are becoming a serious problem, there are no registered chemicals for this crop.  Perhaps predator insects purchased from biocontrol companies could be used.

Flowers & Training

In the early summer the plant is covered with small purple and white flowers.  These flowers resemble tomato flowers in shapes, which are in fact a distant relative.  The flowers are followed by fruits in late summer.  Wolfberry plants continue to flower throughout the season until the first heavy frost.

The plant should be pruned to size in spring and dead wood should be cut out in winter.  To get the heaviest fruiting and the best shaped shrub, it is recommended to prune regularly two or three times a year.  Wolfberry plants usually begin to fruit when they are 2 years old.  Heavy yields can be expected when they are 4 to 5 years old.

Harvesting

The berries are very tender and must be picked carefully or shaken from the vine into clean trays or plastics to avoid spoiling.  During harvest season, plastic cover needs applying to protect fruits from rain damage.  Too much rain can cause black fruits and lose market value.

The fruits are preserved by slowly drying them in the shade on air exchange tablets or by dehydration machine employing a progressively increasing heat exposure over 48 hours.  Later winter or very early spring is the suitable time to gain good quality root barks.  Barks are ground to powder for medicine.

Winter Protection

Supposedly, the wolfberry plant can easily survive winters down to -26° C and hot summers above 37° C where they are gown commercial in Asia.  But the plant has survived winters in Saskatoon, SK and at a few growers' sites in protected area, often near buildings.  To grow it for commercial production in the prairie, it would be worthwhile to experiment on a small scale first with various techniques to aid winter survival.

Find a location with good wind protection.  In the fall, lay down the branches and cover with soil, mulch or saw dust.  Perhaps train the bushes/vines to be low to the ground so the snow can cover them in winter.  It might also be possible to grow this plant as an annual crop for leaves used in cooking, or if plants are started early in a greenhouse and taken outside in June.  Perhaps they could be grown in large pots and overwintered in a sheltered location.  Or it may be that some seedlings will be found that are hardy enough; we won't know until more people try to grow them.

A General Overview of the Wolfberry

By Jessie (Shenjie) Hu
Note: Jessie is an undergraduate student at the University of Saskatchewan.  This article is part of her assignment in her "Fruit Science" class which was edited by the instructor, Bob Bors.