Kiwi Perennials

Commercial Kiwifruit

• Commercial kiwi producers use the "Hayward" variety of Actinidia deliciosa to grow the familiar, fuzzy brown kiwifruit found in grocery stores in the United States. "Hayward" produces large, fine-flavored fruit that keeps for up to six months under ideal storage conditions. Because the vines die when temperatures dip below 10 degrees Fahrenheit, most kiwifruit production occurs in the Central Valley of California, where mild temperatures and fertile soil make it most profitable.

Hardy Kiwi

• Two varieties of perennial kiwi are available to backyard gardeners in colder climates. The first, Actinidia arguta, survives down to -25 degrees Fahrenheit and produces a yellow-green, cherry-sized fruit with a smooth, edible skin. The second, Actinidia kolomikta, can tolerate temperatures in excess of -30 degrees Fahrenheit, though the fruit is even smaller. A. kolomikta fruit is exceptionally high in vitamin C (up to 1 percent of the fruit by weight) and tastes better than the commercial "Hayward" variety.

Viniculture

• Kiwi vines do best in deep, well-drained soil with a pH between 6 and 8. Plant the "Hayward" variety in a protected area away from frost pockets and heavy wind. Hardy kiwi is winter-tolerant, but still prone to spring frost damage. Kiwi thrives in partial shade, which protects them from drought and wind-breakage, especially during the first three years. The plants cannot support their own weight, so train vines on a trellis as you would a grape vine.

Fruit Production

• "Hayward" is a finicky vine that needs 225 frost-free days to successfully set fruit, but will not flower without a chilling period of 600 to 1,100 hours below 45 degrees Fahrenheit. While easier to grow as an ornamental plant, hardy kiwi still requires a prohibitively long frost-free period of 220 days to set fruit, making it difficult for northern gardeners to produce kiwifruit successfully. All kiwi varieties except "Issai" need both male and female plants for fertilization and fruit production.