Pink Leaves, Fuzzy Fruit
Exotic Kiwis Can Do Well in the Northwest
By Rachel Foster 3/3/05

The fruit of the actinidia vine is good for you. Recent research conducted at the University of Oslo, Norway reveals that eating two to three kiwifruit a day yields heart health benefits similar to those of aspirin and may also protect against cancer. Among popular fruits, the kiwi tops the tables for nutrient density, being higher in vitamin C than oranges and a very respectable source of potassium.
The familiar brown-skinned, green-fleshed fuzzy kiwifruit of grocery stores is borne by the female Actinidia deliciosa vine. Originating in China, it acquired the name kiwi when the variety 'Hayward' was put into commercial production in New Zealand. The fruit keeps well, and it is now produced in California and Chile too, assuring a year-round supply of reasonably fresh kiwis.
Actinidia deliciosa can be grown in the Willamette Valley, and is very attractive growing on an arbor. I've heard that getting it to fruit reliably can be tricky, but according to Dr. Bernadine Strik, OSU professor and berry researcher, it just requires some special knowledge, which she was happy to share with me. Plant the vines in a warm location, and protect the trunks against possible frost damage. The beautiful furry, reddish new shoots tend to develop very early and are highly susceptible to frost, so avoid areas where cold air settles.
Don't expect to get vine-ripened fruit off a fuzzy kiwi, says Strik; it won't happen. Your goal should be to get the fruit physiologically mature, so it will ripen off the vine. Strik suggests simply leaving fruit on the vine until the leaves fall off, usually in early November. Gather the fruit and store in a cool place such as the garage, where it will keep for months, and bring individual fruits inside to ripen as needed.
Fruit of the hardy kiwi, on the other hand, will ripen on the vine in a sunny place, and the plant (Actinidia arguta) is much easier to grow. The fruits are smaller, about the size of a large grape, smooth skinned, and are eaten without peeling. They have a shorter shelf-life than fuzzies. I've seen hardy kiwifruit but not the vine. Strik tells me the leaves are smaller and shinier, without any fuzz. The flowers are smaller than those of fuzzy kiwi but more fragrant, and the knobby, leafless stems themselves, like those of other species, are attractive in winter.
Jim Gilbert from One Green World talked about exotic and unusual fruits at Down to Earth last year. The audience had lots of questions about kiwi vines, and Gilbert was bullish about them, but I would seek a taste-test before planting hardy kiwi for its fruit. The vigorous vine takes several years to bear, and flavor varies considerably with variety. When I asked Strik if she had a favorite fruiting kiwi for the garden, she said the all-around winner in taste tests seems to be the hardy 'Ananasnaya.' The vine-ripened fruit is "highly aromatic, with a bit of a tropical, papaya-like note."
Most kiwi vines, hardy or not, are very large and require a sturdy arbor. What's more, male and female flowers are borne on separate plants, so you need two. For people short on space, a sensible approach might be to grow the partially self-fertile variety 'Issai' from Japan. Enjoy the ornamental qualities of a kiwi vine, regarding any fruit you get as a bonus (it will bear larger, more numerous fruit with a pollinizer). 'Issai' fruits younger (as early as the year after planting) and is less vigorous, growable on a trellis or a wall. Strik describes 'Issai' as having "one quarter the vigor and half the yield" of 'Ananasnaya' with a very different flavor.
Because they evolved to twine in trees, actinidias are adapted to a certain amount of shade. Shade reduces fruit production, but the vines grow fine. A third species, Actinidia kolomikta, also sold as arctic beauty kiwi, is definitely a shade plant. It is usually grown as an ornamental: The leaves of male vines are boldly marked with pink and white. The fact that shade-tolerant ornamental vines are hard to come by makes it particularly appealing, and it is demure enough to grow on a trellis. Only well established male vines have really showy leaves.
Dr. Strik has written an excellent handout entitled "Growing Kiwifruit" (Pacific Northwest Extension Publication #507). It is 24 pages long and adorned with lovely drawings. Visit http://extension.oregonstate.edu or your Extension office.
Kiwi vines from One Green World will be available at Down to Earth this spring, and Gilbert himself will be on hand from noon to 1:30 pm April 16 at the Olive Street store to talk about unique and unusual fruit for the home gardener.