Hardy kiwi (Actinidia arguta) is a vigorous, cold-tolerant vine that produces fruit unlike anything in the supermarket: smooth-skinned, grape-sized kiwi you eat whole, skin and all, with none of the fuzz or knife-and-spoon ritual of the fuzzy kiwi sold in stores. It's a different species from that fuzzy kiwi (Actinidia deliciosa), bred for cold climates rather than for size. Growing it is moderately difficult: the vine itself tolerates a lot, but you need both a male and a female plant to get fruit, and a vigorous grower like this demands a trellis strong enough to hold it for decades.
Sowing and planting
Hardy kiwi isn't grown from seed if you want a known, named variety. Seedlings don't come true to the parent plant, and worse, you can't tell a seedling's sex until it flowers years later, so you'd have no way of knowing whether you'd raised a fruit-bearing female or a pollinator-only male. Instead, buy young potted vines from a nursery, already labeled male or female.
This is the detail that catches new growers out: hardy kiwi is dioecious (jargon for a plant where each individual is either male or female, never both), so a single vine never sets fruit on its own. You need at least one male vine within range of your female vines to supply pollen; one male can typically pollinate several females, though the exact ratio depends on the varieties involved, so check the nursery's guidance for the specific male you buy.
Before you plant, put up a strong trellis — a wire fence, pergola, or post-and-wire system built to carry serious weight, since mature vines get heavy with growth and fruit. In zone 6b, plant in spring once the risk of hard frost has passed, choosing a full-sun site with well-drained soil. Space vines about 120 inches (300 cm) apart to give each one room to spread along the trellis. Dig a hole as wide as the root ball, set the vine at the same depth it sat in its pot, and water it in well.
Growing on
Water regularly through the first couple of growing seasons while the roots establish, then ease back once the vine is established, though it still appreciates consistent moisture during dry spells and while fruit is developing. Feed lightly each spring with a balanced fertilizer; too much nitrogen encourages leafy growth at the expense of flowers and fruit.
The task growers most often underestimate is support and pruning. Hardy kiwi is an exceptionally vigorous vine that can put on many feet of new growth in a single season, and an undersized trellis will eventually strain or fail under the combined weight of wood, foliage, and fruit. Build for the long term, with posts set deep and wires or cross-arms rated to carry real weight.
Prune hard every winter while the vine is dormant, cutting back the previous year's growth to a few buds and removing any tangled or crossing canes. Without this annual cutback, the vine quickly turns into a dense tangle that shades out its own fruit and makes harvest difficult. Aggressive pruning feels severe the first time you do it, but it's what keeps the vine productive and the fruit within easy reach.
Harvesting
Hardy kiwi is ready to pick when the fruit yields slightly to gentle pressure, the same ripeness test you'd use on a regular kiwi. Because fruits on the same vine ripen over a period of weeks rather than all at once, you can usually go through the vine several times over the season rather than harvesting everything in one pass.
If you'd rather not wait for full ripeness on the vine, pick the fruit while it's still slightly firm and let it finish ripening indoors at room temperature over a few days. This is useful if birds or wasps are competing with you for the crop, or if frost is forecast before the last fruit has softened.
Problems and pests
Frost damage to young growth or flowers in late spring
A late cold snap after the vine has leafed out or flowered can blacken new shoots and destroy the flowers needed for that year's crop. There's no fixing the damage once it happens; choose a planting site that avoids the lowest-lying frost pockets in your garden, and avoid feeding heavily early in spring, since it pushes soft new growth that's especially vulnerable to cold.
Vine outgrowing or straining its support
Because hardy kiwi grows so vigorously, an undersized trellis, arbor, or fence can bend, lean, or fail within a few years as the vine matures and fruits. Build sturdier support than seems necessary at planting time, and reinforce or replace a structure at the first sign of strain rather than waiting for it to fail under a full crop.
Root rot in waterlogged soil
Hardy kiwi roots dislike sitting in constantly wet soil, which can lead to root rot and a vine that wilts or declines despite regular watering. Plant in well-drained soil from the start, and avoid low spots in the garden where water collects after rain.
Japanese beetles feeding on the leaves
In some regions, Japanese beetles skeletonize hardy kiwi leaves during mid-summer, leaving behind a lacy network of veins. Handpicking beetles into soapy water in the early morning, when they're sluggish, controls light infestations at a home-garden scale.
Varieties worth growing
- Ananasnaya (also sold as 'Anna') is one of the most widely available female varieties, valued for productive vines and sweet fruit; it needs a male pollinator nearby to set fruit.
- Geneva is a cold-hardy female variety bred for northern climates, also requiring a male pollinator to fruit.
- Issai is sometimes marketed as self-fertile, setting at least some fruit without a separate male vine nearby, though many growers still plant a male for a fuller crop.
- Meader is a male variety grown specifically as a pollinator for female hardy kiwi vines rather than for fruit of its own.