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Who doesn’t love the thought of growing fresh, healthy, pesticide-free fruit? And while we’re on the subject, why not consider growing something you don’t find in most backyard settings, something that’ll really wow your visitors? Why not consider kiwis?
Get to Know Kiwis
Kiwi plants are rampant woody vines, at home in lightly shaded woods and clearings, or on trellises and pergolas. They have large, attractive, glossy-green leaves and small, fragrant flowers hidden among their foliage. You’re forgiven if you think the kiwifruit is a tropical crop, unsuitable for growing in the United States. After all, it comes from New Zealand, right? Surprise! While New Zealand is one of the top producers of kiwifruit, kiwis don’t hail from Down Under. The kiwi family, which has about 50 species, comes from eastern Asia, specifically China, Korea, Siberia, and possibly Japan. In fact, China produces the most kiwifruit each year — a mind-blowing 2 million tons.
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So how did an Asian fruit come to be named after a flightless bird from New Zealand? In a word: marketing. Just after 1900, seeds from the fuzzy fruit found their way to New Zealand. From these seeds, three vines sprouted and grew into an industry. At the time, people called these fruits “Chinese gooseberries.” However, New Zealand growers saw an opportunity to rebrand the fruit and get in a little national promotion at the same time. They named it “kiwi,” partly because it resembles the national symbol of New Zealand — that fuzzy, flightless bird, the kiwi — and partly because the people of New Zealand are also known as “Kiwis.”
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Kiwifruit history is full of surprises. For example, the first kiwi vines in America were planted not for fruit but for ornamentation, and many old estates still have ancient kiwi “bowers” scrambling across pergolas, creating secret glades for private conversations and liaisons. One of the reasons no one realized these vines were capable of bearing fruit was because kiwis have male vines and female vines, each bearing delicate white blossoms beneath the leaves. Without both, you get flowers, but no fruit. Honeybees don’t find kiwi flowers attractive; luckily, native solitary bees pick up the slack. There’s one commercial cultivar of hardy kiwi, ‘Issai,’ that’s at least partially self-fruitful, but having at least one male for every 8 to 10 females improves the crop immensely.
Planting and Pruning
If you live in California or the Southeast, you can probably grow the familiar fuzzy kiwi Actinidia deliciosa. It’s hardy to Zone 7, about as far north as Washington D.C. Don’t worry if you’re growing somewhere north of that; you still have options. You’ll just need to grow a different kiwi, specifically arctic kiwi (A. kolomikta) or hardy kiwi (A. arguta). Arctic kiwi is hardy in Zones 5 through 8, and hardy kiwi can grow as far north as Zone 3. In lower latitudes, arctic kiwis appreciate some northern exposure to protect them from sunburn. Arctic kiwis are typically grown for their foliage, which is spectacularly mottled with greens, creams, and pinks, especially on male vines. Both hardy and arctic kiwis have small, smooth-skinned, green or red-blushed fruits, each one about the size of a grape. They both have the same familiar kiwi flavor as fuzzy kiwis, but these tiny cultivars are fuzz-free and can be eaten in one bite. Hardy kiwis are a bit sweeter than fuzzies, while arctic kiwis aren’t quite as flavorful.
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Beyond fruit size and temperature requirements, all three vines have the same basic needs. Kiwis require a winter rest period with temperatures between 40 and 50 degrees Fahrenheit, just like apples and pears. They’re sensitive to warm spells during the dormant season. Once out of dormancy, select a sunny spot with southern exposure, away from walls or other structures that can cause temperature fluctuations.
Kiwis appreciate a windbreak to shelter them from hard winds. Drainage is also critical, as wet soil can cause crown rot. Plant on a hillside, or build up a mound of soil to improve drainage. While wet soil will kill vines, too little water can also be a problem. Be prepared to water more in times of drought.
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Because kiwis are rampant growers, they need lots of room and lots of pruning. Twenty-five feet of growing space per vine isn’t overly ambitious; kiwi plants will quickly fill any space available to them. In fact, they grow so quickly that some states consider them invasive, although they can be kept in check through aggressive pruning. As a kiwi vine ages, its main trunk will thicken to rival small trees, reaching 6 or more inches in diameter. One word of caution on training kiwis on a pergola: Pruning and harvesting will be more difficult.
Heavy pruning also encourages heavy fruiting, so that’s a win-win proposition. Kiwis fruit on year-old wood; regular heavy pruning results in plenty of new opportunities for fruit. Prune in late winter, before the buds begin to break. Once they break dormancy, kiwi vines “bleed” sap profusely. Select shoots that fruited the previous year, and prune them back to four or five buds. Thin out new shoots to remove clutter, leaving the strongest ones for fruiting the following season. Pruning can seem overwhelming, as a healthy kiwi vine can produce up to 15 feet of growth and many side shoots in a single year. Take your time, prune out a bit harder than you think you should, and don’t worry — if you make some pruning mistakes, the vine will grow back.
The most important requirements for happy, healthy kiwi vines are space and support. Kiwis form thick trunks as they age, but they can’t support themselves. Build support structures that’ll last, as a healthy kiwi vine can easily live for 50-plus years. Most growers build heavy T-shaped trellises from pressure-treated 6x6 timbers. Ideally, each T-post should be 6 feet aboveground, with another 2 to 3 feet underground encased in concrete for stability. The crossarms are typically 6 feet long. To build a trellis, space posts 20 to 30 feet apart. Attach guy wires to buried sleeper posts at each end for extra stability and tension. Run five equally spaced wires across the T-bars of the trellis, with the central wire positioned directly above the posts, and tighten with a turnbuckle or ratcheting tensioner to remove any sag. If you build more than one trellis, maintain 15 feet of space between trellises.
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Plant one kiwi vine between each post, directly below the central wire. Use a bamboo stake to support the new vine until it passes the wires. Kiwi vines grow fast, and tend to curl, so you’ll need to tie them up frequently. If a vine curls and hardens before you can tie it to the stake, find the highest bud still on straight wood, and prune the vine off just above it. The vines should reach the wires in their first or second year. Once a vine reaches above the wires, prune it back to the first bud just below the wire, to encourage the buds to form new shoots. Select the topmost two buds and train them to grow along the central wire, one in each direction. Tie the shoots loosely to the wire with soft twine or strips of old nylon stocking.
These two shoots will form the permanent cordons of your kiwi vine, much like a grape vine has a permanent structure. Allow side shoots to arch out across the outer wires of the trellis. Tie them loosely to the outside wire, spaced at regular intervals to allow sun and airflow to reach all parts of the vine. Prune out excess shoots as needed. Your vine should begin fruiting when it’s 5 to 9 years old. Once the vine begins fruiting, it’ll be on these side shoots. If you have the room, trellis one male vine between two female vines; if not, graft a male branch onto each female vine. Just be sure not to prune it off by mistake.
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Kiwi vines are relatively pest-free, although you’ll need to keep a few potential problems in mind. Japanese beetles and leafrollers feed on the leaves. Fluctuating winter temperatures and late spring frosts can damage buds and nip back new growth, reducing or eliminating the year’s crop. Moreover, kiwi vines may affect cats in much the same way as catnip.
Kiwis in the Kitchen
Kiwifruits ripen late in the season, typically in September, with the berries hanging down from the vine like crystals on a chandelier. Allow the fruits to ripen on the vine until they begin to soften. A mature vine can produce 50 pounds or more of kiwi berries, so you’ll have plenty of fruit to harvest and enjoy. The berries contain a high sugar content, and lots of vitamin C, vitamin E, and fiber. Kiwi berries store well for 2 to 3 weeks in the refrigerator, and up to 2 months when conditions are perfect. They do ripen somewhat on the counter at room temperature. They’re great for snacking; using whole or quartered in fruit salads; and incorporating into smoothies, sauces, jams, or whatever your imagination guides you toward. When cooking with kiwis, excess heat will turn their brilliant emerald hue to a muddy olive drab, but it won’t harm their flavor or nutrition.
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Kiwi vines may not be for the gardener who’s short on space, but if you have a clear stretch of land with sun, drainage, and airflow, and you’re handy with trellis building, you can grow this exotic fruit far from its Asian homeland or its adopted home Down Under.
Andrew Weidman lives and writes in Lebanon, Pennsylvania. He’s an officer in the Backyard Fruit Growers, a grassroots group dedicated to helping people grow healthy fruit in their own backyards. Special thanks go to Lester Beachy, Backyard Fruit Growers’ own kiwi expert, for his guidance in all things kiwi.