Issai Hardy Kiwi
Issai Hardy Kiwi
A Self-Fertile Hardy Kiwi with Sweet, Grape-Sized Fruit
Issai Hardy Kiwi (Actinidia arguta 'Issai') is a vigorous climbing vine that produces clusters of sweet, smooth-skinned, grape-sized kiwi berries you eat skin and all — no fuzz, no peeling. Best of all, Issai is self-fertile, so a single vine can fruit (most hardy kiwis need separate male and female plants). It sits at the cold edge of its range here, so give it a sheltered spot and a sturdy support. Whether you're trialing something unusual in Edina, covering a warm arbor in Maple Grove, or adding novelty fruit in a protected Woodbury corner — Issai is an adventurous edible for sheltered zone 4b–5a sites.
Issai Hardy Kiwi Plant Details
| Attribute | Detail |
|---|---|
| Scientific Name | Actinidia arguta 'Issai' |
| Plant Type | Deciduous fruiting vine (hardy kiwi) |
| Mature Length | 10–20 feet on a strong support; vigorous |
| Sun | Full sun to part shade; full sun and warmth ripen the best fruit |
| Water | Moderate — consistent moisture in well-draining soil |
| USDA Zones | 5–9 (Twin Cities is zone 4b–5a — marginal; plant in a sheltered spot, see notes) |
| Soil | Rich, well-draining; amend Minnesota clay-loam with compost. Avoid wet feet. |
| Pollination | Self-fertile — one vine can fruit (yields rise with a second hardy kiwi nearby) |
| Harvest | Late summer to fall; sweet, smooth, grape-sized berries eaten whole |
| Winter Hardiness | Hardy to about zone 5; site in a protected microclimate. Young growth is frost-sensitive. |
Issai Hardy Kiwi Uses in Minnesota Landscapes
Arbors and strong trellises
Issai is vigorous and heavy — give it a sturdy arbor, pergola, or heavy-gauge trellis (not a flimsy lattice) in a warm, sheltered Plymouth spot.
Novelty edible
The bite-sized, fuzzless berries are a fun, kid-friendly treat fresh off the vine in Eden Prairie.
Protected microclimates
Site it against a south- or west-facing wall where heat collects and wind is blocked — these warm pockets improve ripening and winter survival.
Best Time to Plant Issai Hardy Kiwi in Minnesota
Plant in spring (mid-late May) after frost danger passes, giving the vine the full season to establish before its first winter — important for a marginal plant here. Never plant in fall or after mid-October.
How to Plant Issai Hardy Kiwi
- Choose the warmest, most sheltered spot you have — a south or west wall out of the wind, where snow collects.
- Install a strong, permanent support before planting; mature vines are heavy.
- Dig 2–3× the root width; backfill with native soil plus 20–30% compost. Ensure good drainage.
- Water in well and mulch 3–4 inches, kept off the stem.
- Protect young vines from late spring frosts, which can damage tender new growth.
- Prune in late winter to manage its vigor and train to your support.
Watering Issai Hardy Kiwi in Minnesota
First Year Watering Schedule
- Weeks 1–2: Every 1–2 days, deep and slow
- Month 1–2: Every 3–4 days
- Month 3–6: Weekly; keep evenly moist but never waterlogged
- Stop watering 2–3 weeks before ground freeze (typically late October in the Twin Cities).
After Year One
Water deeply during dry spells, especially in summer heat. Consistent moisture supports fruiting on this vigorous vine.
Do I need two plants to get fruit?
No — Issai is self-fertile, which is rare for hardy kiwi. A single vine can fruit, though planting a second hardy kiwi nearby tends to increase yields.
Will it survive a Minnesota winter?
It's at the edge of its range here (rated to about zone 5). The vine can survive in a sheltered, snow-covered microclimate, but late spring frosts may damage tender new shoots. Careful siting is everything.
How big does it get?
Very vigorous — 10–20 feet — so give it a strong support and prune annually to keep it in bounds.
You May Also Like
- Blue Moon Wisteria — another hardy, sheltered-site flowering vine
- Consort Currant — an easy, reliable fruiting shrub
- Heritage Raspberry — dependable everbearing fruit