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  • Growing kiwis in the Rogue Valley

  • Forty years ago, almost no one in America knew what a kiwi fruit was. Botanists knew it as the Chinese gooseberry.
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  • Forty years ago, almost no one in America knew what a kiwi fruit was. Botanists knew it as the Chinese gooseberry.
    Then some New Zealanders started commercial production and changed its name. Today the kiwi is as common in grocery stores as apples. But the home gardener can grow it, too.
    "You can successfully grow the vines really well here," says Drew Matthews, in nursery sales at the south Medford Grange Co-op, "but there's mixed success with how much fruit you get. They are difficult. They don't like heat, but they like sun. You do best to give it morning sun but dappled, afternoon sun from a tree over it. But they don't do well in shade."
    The fruit (genus Actinidia) originated in China and southeast Asia. There are more than 50 varieties, and wild vines climb trees, sometimes growing to 100 feet. Once established, a vine may live 50 years.
    The fuzzy ones we find in grocery stores, Actinidia deliciosa, have the largest fruit and best storage quality. But because growing them in our climate is iffy, the home gardener might do better with two other varieties: A. arguta and A. kolomikta.
    Both varieties have smaller fruit, about the size of large grapes, but they are fuzz-free, so they can be eaten whole, and they actually are sweeter than their larger cousins. These two varieties are known as "hardy kiwis" because they can survive low temperatures.
    "The hardy kiwi needs a lot of special care," says Maud Powell, small farms agent at Southern Oregon Research and Extension Center in Central Point. She recommends starting it in a 5-gallon pot.
    "You want to protect the roots; they are easily damaged by frost."
    Powell says keeping the plant in a pot the first spring and summer and then moving it indoors for the first winter gives the roots a chance to grow strong. After frost danger has passed the second spring, it can be planted in the ground, but use mulch for root protection. The trunks also are susceptible to frost damage, and it is a good idea to protect the growing trunks in winter for a few years with foam pipe covers. Once established, hard kiwis can withstand temperatures 25 degrees below zero.
    Kiwis require males and females to produce. One male can pollinate up to eight females. They begin producing fruit anywhere from two to five years after planting, and a mature vine should yield 25 pounds of fruit.
    Kiwis require well-drained soil and can do well in raised beds. They prefer a soil pH between 5 and 6.5 and need to be protected from strong winds. The Oregon State University Kiwi Growing Guide (extension.oregonstate.edu/catalog/pdf/pnw/pnw507.pdf) suggests adding compost, rock phosphate and kelp meal to the hole when planting. Kiwi roots are susceptible to fertilizer burn, so it's recommended that you fertilize when planting and in the spring.
    The plants need a strong trellis for support. Many different styles are used, but a T-bar is most common. The posts should be at least 8 feet tall and at least 6 inches in diameter, buried 2 to 3 feet deep. Two-by-sixes on top of the posts can be used for the T, with cross-bracing for extra strength. The OSU guide gives complete trellis instructions. It also provides a pruning guide.
    Plants can be spaced from 8 feet apart for A. kolomikta to no more than 15 feet for A. arguta. They need to be pruned regularly to keep them healthy and producing. Fruit is produced on 1-year-old wood. Males can be pruned back after flowering. Females need to be cut back one-third in winter after fruiting or very early in spring.
    The plants need regular water, particularly during summer heat, and roots must never be allowed to totally dry out. Deep watering once or twice a week is preferable. Organic mulch will help retain moisture.
    Yes, it takes some work. But in exchange, you get a beautiful, ornamental vine and fruit that is very high in vitamin C — not to mention extremely tasty.
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