Actinidia chinensis Seeds | Kiwifruit
LATIN NAME: Actinidia chinensis
COMMON NAME: Kiwifruit, Chinese Gooseberry
Plant Profile
Kiwifruit is a vigorous climbing vine, 5-10 m, with large heart-shaped leaves and, in late spring, small white flowers that turn cream as they age. The fruit is a berry with green flesh, black seeds and a hairy brown skin, and it ripens late in the season.
The plant is dioecious: male and female flowers are borne on separate vines, and a female needs a male within about 15 m for pollination. That is the single most important thing to know before planting, and the most common reason a vine flowers for years without fruiting.
Actinidia chinensis comes from central and southern China, where it climbs through forest edges and was collected for its fruit long before it was cultivated commercially. The Haywood selection is a female cultivar, and it is the basis of most of the world’s green kiwifruit plantings.
Science & Biotechnology
Kiwifruit contains actinidin, a cysteine protease that breaks down proteins and is the reason the fruit can be used as a meat tenderiser. It also makes raw kiwifruit unsuitable for setting gelatine, and it can irritate the mouth in people with an allergy to the enzyme.
The fruit is exceptionally high in vitamin C, with around 90 mg per 100 g, higher than an orange. The vitamin is stable in the fruit because the low pH protects it, which is why stored kiwifruit keeps its value for months.
Dioecy in Actinidia is controlled by a pair of sex-determining genes, and the mechanism is one of the clearer examples of sex chromosomes in plants. Female vines have two X chromosomes and males have one X and one Y, and the Y carries the genes that suppress female development.
Uses & Benefits
The fruit is eaten fresh, sliced into fruit salads, blended into smoothies and used in desserts. It is also dried, juiced and used as a source of vitamin C and of the enzyme actinidin for tenderising.
In the garden the vine is grown on a strong pergola or a wire frame, where it doubles as a shade plant and a crop. It needs a long warm season to ripen fruit, and in cool climates it is grown under cover. Commercially the crop is a major industry in New Zealand, Italy, Chile and China, and the seed is sold to growers and to home gardeners.
Growing from Seed
Sow at 20-25°C, 0.5 cm deep, on the surface of a moist seed mix. Germination takes three to six weeks and is uneven; stratification for four weeks improves it. Seedlings are variable in sex, so buy named plants if you want reliable fruit.
Plant out in full sun, sheltered from wind, in deep, fertile, well-drained soil. Train a single stem to a wire at 2 m, then form two permanent arms along the wire. Prune in winter to remove the wood that fruited last year, since fruit is borne on new growth. Water regularly and mulch; the vine has shallow roots and resents drought.
Our Take
A vine for a warm wall or a polytunnel, worth the wait of three or four years for fruit that tastes nothing like the ones in a supermarket.
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