IN THE ARBORETUM TODAY
by Alfredo Chiri
Actinidia chinensis – Actinidiaceae
Var. Elwood – donated by: CRFG/Roger & Shirley Meyer and planted in 1991
Var. Vincent – donated by: CRFG/Roger & Shirley Meyer and planted in 1991
Common names: Kiwifruit, Chinese gooseberry, Yang-tao
The Kiwifruit is one of the few fruits that have been domesticated this century. Native to China where it was a wild plant, by the 70’s it was developed in New Zealand into a new fruit. There are about 60 species, and their genus varies with every individual species, giving an unlimited chance for diversity in the breeding programs.
The Kiwi plant is a vigorous, deciduous shrub that may climb to 30 feet. The 5-inch leaves are densely hairy underneath. When young, they are bright red, changing to brown at maturity. The fruit comes from a sturdy vine that grows even in snowy climates but is most tender when the young
sprouts grow in the spring.
For the vine to fruit, male and female flowers are a must. The flowers are white, attractive and fragrant, changing to yellow with age. The female flower is many-celled, and it produces a fruit with many seeds. Pollen must be transferred from the flowers on staminate plants (male) to those on pistillate ones (female). The flowers seem to be easily adapted to bee pollination rather than wind. The structure of the flower, needing numerous pollen grains on their stigma to fertilize the ovules and
produce numerous seeds, indicates that insects are the best pollinators.
The Kiwifruit is an oval or oblong fruit with brown skin densely covered with short, stiff brown hairs. The flesh, firm until fully ripe, can be green or sometimes yellow, with a white succulent center from which many fine, pale lines radiate. Between these lines are many dark seeds that are unnoticeable during eating.
Kiwi vines will tolerate part shade but prefer a sunny location where they can climb in some type of trellis system. The vines would not perform well in hot dessert climates, and they should be protected from strong winds. Prune heavily in the dormant season, and train them like spur grapes. The vines, besides bearing fruit, also have attractive foliages. They prefer a well-drained soil that is rich in organic matter. Kiwis do not tolerate salty soils.
The ‘Vincent’ kiwi can be grown in mild areas with fewer than 100 hours of chilling. In mild winter areas the vines may retain their leaves and fail to flower the following spring. The flowers can be damaged by late spring frosts; also the fruit, which requires a growing season of at least 240 frost-free days to become sweet.