How to Grow Kiwi Fruits USA

Quick Facts

Factor	Value
Drainage	Fertile, well-drained, slightly acidic soil enriched with organic matter -- roots rot in waterlogged conditions (RHS). PSU gives soil pH 5-6.5 for hardy kiwi and warns roots burn easily, so fertilizer should be applied cautiously.
Lifecycle	Vigorous, deciduous, woody climber. Dioecious (male and female flowers on separate plants) -- RHS: female varieties ('Hayward', SOLISSIMO, 'Ken's Red') need a male or self-fertile plant nearby; 'Issai' (A. arguta) and 'Jenny' (A. deliciosa) are self-fertile and need no pollinator. PSU is specific about the ratio for hardy kiwi: roughly one male to six females. Fruit size differs by species: A. arguta gives smaller, smooth-skinned fruit about 2.5cm (1in) long; A. deliciosa gives larger, furry-skinned fruit 3-5cm (1.25-2in) long (RHS).
Edible parts	fruit
Documented problems	4 diseases, 4 pests

At a Glance

Diseases

Grey mould

moderate

Botrytis cinerea

Soft brown fruit decay; Fuzzy grey-brown mould

Named by PSU as "botrytis rot"; recorded against the existing grey mould (Botrytis cinerea) entry.

Phytophthora root rot

high

Named independently by both RHS ("Phytophthora root rot") and PSU ("Phytophthora crown and root rot") -- the strongest-corroborated risk for this crop, both sources agreeing waterlogged/heavy soil is the trigger.

Honey fungus

low

Armillaria spp.

Named directly by RHS (honey fungus).

Sclerotinia blight (kiwi)

moderate

Sclerotinia sclerotiorum

Named directly by PSU ("sclerotinia blight").

Pests

Glasshouse red spider mite (two-spotted spider mite)

moderate

Tetranychus urticae

Named directly by PSU as "two-spotted spider mites" (Tetranychus urticae).

Tortrix moth caterpillars

low

Tortricidae

PSU names "leaf rollers" generically; recorded against the existing tortrix moth caterpillar entry as the common leaf-rolling culprit rather than inventing a separate generic entity.

Japanese beetle

moderate

Popillia japonica

Named directly by PSU.

Thrips

low

Thysanoptera

Named directly by PSU as "thrips" without a specific species.

Soil & Growing Conditions

Water: RHS: drought and drying winds cause drooping leaves, brown leaf edges and even complete leaf loss -- consistent watering matters, especially while establishing.

Growth Stages

Stage	BBCH	Notes
Planting and support	0	Plant in spring once soil and weather have warmed, in a warm, sunny, sheltered site, ideally against a south- or west-facing wall (RHS). Space 3-4.5m (10-15ft) apart (RHS); PSU gives 10ft for hardy kiwi specifically. Needs a large, sturdy support -- a pergola, archway or strong wires -- given how vigorous the vine is; PSU notes hardy kiwi can gain 20ft of growth in a single season. Prune immediately after planting (RHS).
Framework training	3	RHS: cut the strongest shoot back to 30cm (1ft), remove weaker shoots, then train a horizontal tiered espalier framework on wires spaced 40-50cm (16-20in) apart.
Pollination	6	Dioecious -- male and female flowers grow on separate plants (RHS; PSU). Female varieties (Hayward, SOLISSIMO, Ken's Red) need a male, or a self-fertile variety, planted nearby; Issai and Jenny are self-fertile and need no pollinator (RHS). PSU gives roughly a 1:6 male-to-female ratio as the practical rule for hardy kiwi.
Summer and winter pruning	3	Essential twice a year given the vine's vigour (RHS; PSU). Summer (June on): pinch fruiting shoots back to 4-5 leaves beyond the fruit, non-fruiting laterals to 5 leaves (RHS); PSU gives 4-6 leaves beyond the last flower. Winter (December-March per PSU): shorten horizontal arms by a third, existing laterals to 3-4 buds, and on mature plants renew a quarter to a third of the oldest laterals to about 5cm (2in) from the base (RHS); PSU notes as much as 70% of the wood is removed during dormant pruning.
Fruiting and harvest	8	RHS: fruiting begins 3-4 years after planting. PSU gives a longer 5-9 years for hardy kiwi specifically -- plausibly reflecting grafted cultivar stock (RHS's figure) versus less-selected rooted-cutting stock, rather than a real contradiction. RHS: fruit quite often won't ripen fully outdoors except in long hot summers -- pick before the first hard frost and ripen indoors. PSU: a mature plant yields 50-100lb of fruit (50lb closer to the average); vine-ripened fruit runs about 18-25% sugar.

Harvest & Storage

When to pick: RHS: fruit quite often won't ripen fully outdoors except in long hot summers -- pick unripe fruit before the first hard frost and ripen it indoors near a fruit bowl at room temperature, which can take several weeks; ripe kiwis yield slightly when squeezed. PSU: fruit harvested early will "after-ripen" off the vine; vine-ripened fruit runs about 18-25% sugar.

Storage

RHS: once ripe, refrigerate for up to about 2 weeks. PSU: fruit picked early and refrigerated will keep in a cooler for up to 2 months.

Sources

1. Penn State Extension - Hardy Kiwi in the Home Fruit Planting

   Roots burn easily -- apply fertilizer cautiously. Plants usually purchased as rooted cuttings or potted plants, spaced 10ft apart; a pergola system suits the vine's high vigour. Dioecious: male and female flowers on separate plants, roughly a 1:6 male-to-female ratio needed; Issai is the only self-fertile variety noted. Growth: can gain 20ft of growth in a single season. Yield: doesn't bear fruit until 5-9 years old; a mature plant yields 50-100lb of fruit, 50lb closer to the average. Pruning: as much as 70% of wood removed during dormant pruning (December-March in Pennsylvania); summer pruning cuts terminal growth back to 4-6 leaves beyond the last flower. Harvest/storage: fruit harvested early will "after-ripen" and keeps in a cooler for up to 2 months; vine-ripened fruit runs about 18-25% sugar. Pests/diseases: Phytophthora crown and root rot, botrytis rot, sclerotinia blight; two-spotted spider mites, leaf rollers, thrips, Japanese beetles.

These source is specific to this region. The full list of 2 sources behind this guide (Penn State Extension, Royal Horticultural Society) is in the references of our UK guide to kiwi fruits; they describe the plant itself, which is the same wherever it grows.