by Nicko Rubin
Sprawling tendrils covered in lush green foliage, shroud clusters of grape sized, smooth skinned, green kiwi berries. Hardy Kiwi are one of a slew of highly nutritious hardy fruits from northern asia, which are well suited to our growing climate; seaberry, honey berry or haskaps, goji, and the controversial autumn olive (AKA silverberries), to name a few. Native to high mountain forests and thickets in China and across Asia, hardy kiwi vines have long been cultivated for both fruit and ornamental purposes.
Hailed as a “superfood”, hardy kiwi is a good source for over 20 vitamins and minerals. Five times the vitamin C as an orange by weight, 60% more vitamin E than avocado, and more potassium than bananas. The fruit is also a good source of vitamins B6, B2, and folate. The berries provide numerous healthful plant compounds including antioxidants, carotenes, and flavonoids. A compound particular to kiwi, acinidin protease, aids in the digestion of animal protein and facilitates general function of the digestive tract. The combination of vitamins, minerals, and plant compounds make the hardy kiwi one of the most powerful cancer preventing foods. In fact, hardy kiwi has been used in chinese medicine for the direct treatment of cancer.
And the flavor? Excellent. The berries are very sweet with a good balance of tartness, overlaid with rich fruity flavors ranging from kiwi to pineapple and raspberry.
Two different species are well suited to the Northeast, the hardy kiwi (actinidia arguta) which are hardy to -25 degrees, and the arctic kiwi (actinidia kolomikta) which is hardy to -40 degrees. The vines are dioecious, meaning male and female flowers are born on separate plants, thus both a male and female plant are required for pollination and fruit set. One male can pollinate several females and only the females bear fruit.
The vines require a well drained soil and will grow nicely in part shade, but will produce the most fruit in areas where they have the full sun. Plant in a spot protected form the strongest winds and with good air drainage as the leaves are tender and new growth can be set back by late frosts. Hardy kiwi grow as vigorous wrapping woody vines and should be given a structure to climb. They can be grown on an arbor, trellis, or fence; the most impressive plants I have seen were blanketing an old maple stump about 12 feet tall at Steve Bryer’s nursery in East Hampton, Massachusetts. The vines, though vigorous, are typically slow to mature (4-6 years for a first crop), however yields can be over 100 lbs per vine.
To have a fruit we can grow locally which provides so much in terms of nutrition and flavor may be a great blessing. There is still much to be discovered with regard to cultivating hardy kiwi. Current breeding projects are producing improved varieties and extension agencies are working develop the optimal maintenance strategies. The future looks bright for the Hardy Kiwi.
Nicko Rubin owns and operates East Hill Tree Farm, a nursery and permaculture consulting farm for fruit trees, nuts, and berries in Plainfield, VT.