The vines tolerate colder conditions and are hardy to zone 5. The aromatic, flavorful fruits are much bigger than other varieties, up to 1 oz., more block-shaped and a nice lime green. Kiwis are superb eaten fresh in mixed salads and are rich in vitamins and potassium. The vines are very ornamental, even when not in fruit. Use trellises for support. Plant with a male pollinator to ensure fruit set.
Hardy kiwis prefer well-drained, fertile soil high in organic matter. Plant in sunny to part-shade sites where you can provide supports. Vines can grow up to 15 to 40 feet. Set trellis posts around 8-10 feet apart.
Do not feed the first year of planting. In spring the second year, broadcast 2 ounces of 10-10-10 fertilizer around each plant. Fertilizer can also be supplied as compost or as an organic liquid feed. In winter, protect the root zone with 4-6” bark mulch or compost. Kiwis prefer thorough watering, a good root soaking, rather than daily light misting.
During winter, in the dormant season, remove canes that fruited the last season, and any diseased, dead or tangled branches. Protect the trunks of young vines from cracking in cold spells by wrapping with cloth. During summer, in the growing season, cut side branches that do not carry any flowers back to the wiring on the trellis.
Hardy kiwi female plants are wind-pollinated from male plants. In early summer, vines bear white flowers on the previous season’s growth. Light green fruits form in summer well into fall, and ripen late in the season. Plants start to yield well by their fourth year, and once established, can live to around 50 years. Their nice foliage and habit offer ornamental interest through the season.
Fruits are borne in clusters along the stems, and mature in mid to late September to October, which is after the first frost date in northern regions. Fruits can be picked early, when still hard and green, and stored to ripen in the refrigerator. Grape-sized, smooth-skinned hardy kiwis bruise easily. Fully ripe fruits have black seeds when cut open and can be eaten without peeling. Hardy kiwi fruits have excellent flavor and can be dried or used to make wine. Kiwi berries are very high in vitamin C.