How to grow Kiwifruit in New Zealand

Where to plant

Kiwifruit need full sun, shelter and deep, rich, free-draining soil. A mostly north-facing spot protected from strong wind is ideal, as wind tears the large leaves, snaps young shoots and marks fruit. Waterlogged soil kills vines, so avoid low, wet ground.

The vines are extremely vigorous, so plan the support before you plant. Each vine needs about 4 to 5 m of strong pergola, fence or T-bar trellis, and a mature vine with fruit is very heavy. Kiwifruit need some winter chilling and a frost-free spring: frosts after budburst burn the new shoots and flowers, and autumn frosts can damage fruit still on the vine.

• Northland, Auckland, Waikato and Bay of Plenty: kiwifruit grow very well. Psa is present in almost every North Island kiwifruit district, so practise good hygiene and use copper protection.
• Central North Island, Wellington and Nelson and Marlborough: grow well in sheltered spots free of late spring frosts. Nelson, Motueka and Golden Bay are South Island kiwifruit districts.
• Canterbury, Otago and Southland: possible in a sheltered, frost-free spot against a warm wall, but late spring frosts often damage the new growth.
• Central Otago: not recommended. Frosts into November burn the new shoots, and the frost-free season is too short to ripen the fruit.
• South Island gardeners: the South Island is still free of Psa-V, and moving any kiwifruit plants, cuttings, budwood, seed for propagation or pollen from the North Island to the South Island is prohibited. Buy South Island plants from a certified South Island source.

Choosing a variety

The newer gold and red kiwifruit, such as SunGold, are licensed commercial varieties and are generally not available to home gardeners. Whatever you choose, buy plants only from a nursery certified under KVH's Kiwifruit Plant Certification Scheme or Plant Pass, and never take cuttings or budwood from someone else's vine.

How to plant

1. Build the pergola, T-bar or fence first. It must take the weight of a mature vine in fruit.
2. Plant dormant vines in winter. Dig a hole twice as wide as the root ball and no deeper, enriching the soil with compost. Do not plant too deeply or pile compost against the trunk.
3. Plant at the same depth as in the pot, tease out circling roots, water in well and mulch, keeping mulch off the trunk.
4. Plant the male within a few metres of the females, or in the middle of a row of them, so bees can carry pollen between them.
5. Choose one strong shoot as the trunk and tie it to a stake. When it reaches the top of the support, pinch it out and train two leaders along the wires or pergola in opposite directions.

Watering and feeding

Kiwifruit have shallow roots and dislike drying out. Water deeply once or twice a week through spring and summer, more in hot, dry weather and while fruit is sizing, and keep a thick layer of compost or aged manure mulch over the root zone. Do not keep the soil waterlogged, which damages roots and can cause poor budbreak.

Feed in spring and again in early summer with a fruit or citrus fertiliser, and through the year with organic matter such as compost or blood and bone. Keep feeding even: heavy nitrogen pushes soft, leafy growth that is more prone to Psa.

Pruning and care through the year

• Winter pruning, June to August: remove the canes that fruited last season and tie down new, healthy canes along the wires to fruit this season. On male vines, prune lightly after flowering instead.
• Summer pruning, December to February: shorten the long, whippy shoots several leaves beyond the last fruit, and cut out tangled growth so light and air reach the fruit.
• Prune in dry weather and clean secateurs with methylated spirits or a disinfectant between vines, as Psa spreads on tools and enters through cuts.
• Apply a copper spray to protect leaf scars and cuts after harvest and at leaf fall, and again at bud burst in wet springs, following the label.
• Bees do most of the pollination, so avoid spraying anything harmful to bees while the vines are flowering in late spring.
• Pick up or harvest all fruit. Birds spread seed from discarded fruit, and KVH asks people to report wild and unmanaged kiwifruit vines.

Harvesting

Kiwifruit do not ripen on the vine in the way most fruit does. Pick them in autumn, about March to May depending on district and variety, when they are full size and firm and the seeds inside a test fruit have turned black. In frost-prone areas, pick before the first autumn frost.

Ripen the fruit at room temperature until it gives slightly when pressed; putting a ripe apple or banana with them speeds this up. Firm, unripe fruit keeps for weeks in the fridge, so take out a few at a time to ripen.

Growing in pots

Kiwifruit vines are too vigorous for most pots. A self-fertile type in a very large container, at least 50 cm wide, on a strong trellis can work for a few years, but crops are small and the vine needs constant water.