How to Grow Hardy Kiwi, a Cold-Tolerant Vine That Produces Sweet Mini Kiwis

Hardy kiwi, also known as kiwiberry, is a hidden gem of gardens in zones 3 to 8. “It’s vigorous, pest-resistant, and produces fruit that is essentially a hairless, sweeter version of the grocery store variety,” says Sally McCabe, associate director of community education at the Pennsylvania Horticultural Society. 

Here, our experts explain how to choose the right varieties of hardy kiwi (Actinidia arguta) and the best care practices to ensure these tiny delicacies thrive.

Best Varieties

The best variety varies by region, so McCabe suggests checking with local garden centers or nurseries. However, Issai is best for small spaces. “It's a smaller vine and uniquely self-fertile, meaning you don't strictly need a male pollinator,” she says, “though you’ll get more fruit if you have one.” Geneva is an early ripener, which she says is excellent for regions with shorter growing seasons or unpredictable early autumn frosts.

Planting Instructions

Plant your kiwi in early spring, as soon as the soil can be worked, but before the heat of summer sets in. “This gives the vine a full growing season to establish its massive root system,” McCabe says. “While the vines are incredibly cold-hardy—some surviving down to negative 25 degrees Fahrenheit—they have a fast wake-up habit.” 

This means hardy kiwi tends to push tender new growth at the first sign of a thaw. Plant them in a spot with northern exposure or one that stays slightly cooler in early spring. “This keeps the plant dormant longer, protecting the new buds from the yo-yo frost cycles common in our region,” she says. “Mine is quite happy along a moderately shady driveway on the north side of my house.”

Start with an established plant. “Never start from seed unless you are a hobbyist breeder,” McCabe says. “Seed-grown kiwis are unpredictable, take a decade to fruit, and you won't know the sex of the plant until it flowers.”

Here's how to do it:

1. Purchase your plants: Buy potted plants that are between one and two years old from a reputable grower.
2. Pick your site: Choose a spot with good sun for fruit production and well-drained soil. Kiwis hate wet feet.
3. Provide plenty of room: Space your plants 10 to 15 feet apart.
4. Get digging: Dig a hole twice as wide as the root ball. Plant at the same depth it was in the pot.
5. Don’t forget support: Install a heavy-duty trellis or pergola immediately. These vines can grow 20 feet in a year and will quickly overwhelm a flimsy structure.

Care Instructions

McCabe provides these care instructions for thriving hardy kiwi:

• Water: Keep soil consistently moist for the first two years. Once established, they are moderately drought-tolerant, but fruit will shrivel without regular water during dry spells.
• Soil: They prefer slightly acidic soil (pH 5.5 to 6.5). Mulch with compost annually to add nutrients and retain moisture.
• Fertilizer: Apply a balanced organic fertilizer in early spring. Avoid over-fertilizing with nitrogen, which encourages lush leaves but very little fruit.

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Support

Hardy kiwi vines are unbelievably vigorous. “A flimsy plastic trellis will collapse under the weight of a mature vine in a few years,” McCabe says. “A sturdy pergola, a 4-wire T-bar trellis (similar to what is used in vineyards), or a split-rail fence is necessary to support the sheer biomass and the heavy clusters of grape-sized fruit.”

Matt Tutt, head gardener and food grower at Aguacateros, uses metal piping for his kiwi. “It looks a bit like the structure sometimes used as scaffolding on building sites,” he says. “Otherwise I’d end up with a sprawling mess of vines.” 

Pruning

Without pruning, the hardy kiwi becomes a tangled jungle with very little fruit. “Prune heavily in the winter to remove old wood and thin out the canopy, ensuring sunlight can reach the interior of the vine to ripen the berries,” McCabe says. “I weave my prunings into wreath shapes and save them for craft projects.” 

Perform dormant pruning in the winter to remove 70 percent of the previous year's growth; summer pruning keeps the vigorous water sprouts from tangling.

Pollination

Most hardy kiwis are dioecious, McCabe says, meaning you need both a male and a female plant to get fruit. “You need one male plant for every six to eight female plants,” she says. “The male doesn’t produce fruit; its only job is to provide pollen. Ensure they are planted within 50 feet of each other so bees can easily commute between them.”

Issai is an exception and a self-fertile cultivar—though it produces better yields when a male plant is nearby.

Fruit Expectation and Harvesting

Tutt planted his kiwi about four years ago, and they are well established and flowering. However, they have yet to bear fruit. “It will usually take around four or five years from the time of planting,” he says, “but that also depends on how established the kiwi vine is when planted.”

Hardy kiwis are not for impatient gardeners, McCabe says, but should be viewed as an investment. “Harvest them when they are slightly soft to the touch, similar to a peach,” she says. “If a frost is imminent, they can be harvested and ripened in a paper bag with an apple.” 

Store firm kiwis in the refrigerator for up to two months and bring them out to ripen at room temperature as needed.