Heart-shaped leaves clothe a vine that climbs well over 15 feet, hung in early summer with fragrant whitish-green flowers carrying violet-red anthers. Hardy kiwi (Actinidia arguta) bears smooth, thin-skinned berries, sweeter than the common kiwi and tangy as gooseberry; give it a sturdy support and cool soil, and it will crop through autumn.
| Botanical name | Actinidia arguta |
|---|---|
| Common name | hardy kiwi |
| Family | Actinidiaceae |
| Type | vine |
| Height | 6 feet (5 m) |
| Planting distance | 6 to 10 feet (2 to 3 m) |
| Exposure | full sun, no wind |
| Soil | cool, rich, light, well-draining, not chalky |
| Planting | fall, spring |
| Harvest | early autumn to mid-autumn |
Hardy kiwi, sometimes called Siberian kiwi, is a tendril-forming vine native to Asia. It belongs to the Actinidaceae family, just like its relative the more common kiwi (Actinidia chinensis or Actinidia deliciosa).
Hardy kiwi can vine to heights over 15 feet, and it’s covered with lovely heart-shaped deciduous leaves. Blooming begins at the beginning of summer: whitish-green flowers with violet-red anthers appear. They’re very fragrant and bear a lot of nectar for bees. When the specimen you’ve planted is a female one, or if it’s a self-pollinating variety, the blooming is followed by the emergence of oval berries. Each berry is smaller than that of the regular kiwi, and its skin is smooth and thin. They’re also sweeter and contain even more vitamin C and calcium.
The tangy taste of hardy kiwi is very similar to that of gooseberry.
Sowing Siberian kiwi takes place at the beginning of spring, but you can also start your seedlings indoors or in a greenhouse anytime in fall. If you’re growing kiwi from seed taken from the current year’s fruits, then you must keep them in the refrigerator for 8 to 12 weeks. This simulates spending a winter out in the cold, which is necessary to trigger germination.
Fall is when you should transplant your hardy kiwi to the ground. Note, however, that if you live in places where winter is harsh, it’s best to transplant it in spring so that it can settle in during the summer before facing its first cold winter.
Dig the planting hole 2 feet (50 cm) across, and make sure you space the plants by 6 to 10 feet on all sides.
Hardy kiwi is a very hardy plant. It can resist colds down to -4°F (-20°C). In most parts of the temperate world, you can grow it outdoors directly in the ground without any problems at all.
If ever you’ve planted hardy kiwi varieties that aren’t self-pollinating, then you should plant at least one male specimen so that all the other female specimens may find pollen to bear fruit. One single male is usually enough to fertilize 5 or 6 female specimens.
The Siberian kiwi vine requires a trellis that’s sturdy and strong (lattice, pergola, tree trunk, fence…). Keep the soil cool in summer thanks to regular watering (1 or 2 times a week when the weather is hot). A layer of plant mulch 4 to 6 inches thick (10 to 15 cm) will be a big help to your hardy kiwi on those hot days.
Hardy kiwi isn’t very vulnerable to attack from pests, except for red spider mite. This pest typically appears when the weather is both hot and dry.
A hardy kiwi usually needs 2 to 3 years after planting before bearing its first few fruits. When fruiting has started, you’ll have a continuous supply from early autumn to mid-autumn, so make it a point to check on the vine every couple days to see what’s ripe for the picking.
You can also pick a hardy kiwi even if it isn’t quite ripe yet: it’ll ripen still even when you’ve picked it off the plant.
In any case, expect a picked hardy kiwi to keep for at most one or two weeks. You usually eat it fresh and raw; there’s no need to peel it.
From seed to picked fruit, hardy kiwi follows a fairly fixed calendar. Here is what happens when, and the one thing that matters at each stage.
| Stage | When | What matters |
|---|---|---|
| Sowing | Beginning of spring, or in fall under cover | Seed from this year’s fruit needs 8 to 12 weeks in the refrigerator before it will germinate |
| Planting out | Fall, or spring where winters are harsh | Space the plants 6 to 10 feet apart in rich, light, well-draining, non-chalky soil |
| Watering and mulching | Through summer, when the weather is hot | Water once or twice a week and keep the soil cool under a thick plant mulch |
| First fruits | 2 to 3 years after planting | Non self-pollinating vines need a male nearby before any berries set |
| Harvest | early autumn to mid-autumn | Pick over the vine every couple of days; fruit keeps only one or two weeks |
Meet those few dates and a single vine will keep the fruit bowl full for two months.
Hardy kiwi is usually sold either as a named female needing a male nearby, or as one of the few self-fertile selections that will crop on their own. The table below sets out the varieties most often found in garden centres and mail-order fruit catalogues.
| Variety | Pollination | Fruit | Season | Vigour |
|---|---|---|---|---|
| Ananasnaya (Anna) | Female, needs a male | Green flushed red, aromatic | Mid | Very vigorous |
| Michigan State (MSU) | Female, needs a male | Large green berries | Late | Very vigorous |
| Issai | Self-fertile | Small, green, very sweet | Early | Compact, good in pots |
| Jumbo | Female, needs a male | Largest green berries | Late | Very vigorous |
| Weiki | Female, sold with male partner | Green, red-blushed, sweet | Mid | Vigorous, very hardy |
| Ken’s Red | Female, needs a male | Purple-red skinned | Late | Vigorous |
| Geneva | Female, needs a male | Green with red blush, sweet | Early | Vigorous |
| Meader | Male pollinator only | None | Flowers mid-season | Vigorous |
This kiwi’s taste is ideal to give a delicious twang to your fruit salads. It’s also surprisingly tasty in sweet & sour dishes. Those who like baking can make pies, muffins, and even ice cream from it. Another option to make the most of your ripe hardy kiwis is to drink them: blend them to prepare juice, slice them into punch, or distill them to brew wine. Lastly, hardy kiwi preserves are also easy to succeed: jam, sauce and jelly.
Some varieties are easier to find than others. For instance, the ‘Issei’ or ‘Issai’ variety is easier to get your hands on. It bears fruits that are very sweet! It’s a self-pollinating variety.
