Kiwis have become a staple in the produce department at grocery stores and now they are becoming more commonplace in the backyard as well. The lovely perennial vines create a unique cover for trellises and arbors. And kiwi fruits are good for you. They are packed with vitamin C, potassium, vitamin E, high fiber, and are low fat.
Semi-Tropical, Hardy and Super-Hardy Kiwis
It may surprise you to know that kiwis will thrive in just about any climate that experiences at least a month of below 45 degree F temperatures in winter. The vines need a period of cold to set fruit.
The kiwis available at the grocery store, Actinidia deliciosa, are native to New Zealand. They are semi-tropical and are best suited for zones 7 through 9. Look for these varieties: ‘Blake’, ‘Elmwood’, and ‘Hayward’.
Hardy kiwis, Actinidia arguta, and super-hardy kiwis, Actinidia kolomikta, have smooth, edible skin and smaller fruits. They are very prolific and the flavor of the fruit is sweet. Grow A. arguta in zones 4 through 7 and A. kolomikta is cold tolerant to zone 3. ‘Anna’ and ‘Dumbarton Oaks’ are two common A. arguta varieties. ‘Arctic Beauty’ is A. kolomikta.
Cultural Requirements for Kiwis
Plant your kiwi vines in well-drained soil with a pH between 5.0 & 6.5. They will produce fruit in partial sun. The hardy & super-hardy types are particularly shade tolerant. It’s important that they are in a location that is shielded from glaring winter sunlight and away from cold spring air pockets that might damage the early blooming flowers.
Kiwis are Dioecious
Plant a male kiwi vine within 35 to 50 feet of a female kiwi vine for proper pollination. A single male plant can pollinate several female plants. Hand pollination is an option for a small number of plants. Just pick a male flower and rub it on a female flower.
Kiwis roots are sensitive to fertilizer so always use a slow release fertilizer when feeding. Apply an all-purpose, slow release fertilizer at planting time. After the first year feed in early spring before the leaf buds break and again in summer after the flowers fade. Kiwis are excellent candidates for organic gardens because they respond well to options such as cow manure.
Staking Kiwi Vines
The kiwi is a vine that needs staking. This helps support the fruits, allows sunlight to reach the leaves and keeps the vines off the ground. You can train them to a guide wire and stake system similar to grapes or any vertical structure such as a fence or trellis.
Pruning Kiwi Vines
It’s important to prune kiwi vines to keep the shape tidy and for fruit production. Fruits are borne on the current season’s growth that emerges from the previous season’s canes. During the first year work on developing a central trunk that is trained to the support. Thereafter prune during the dormant season. Remove dead and diseased wood and stems that fruited during the previous year. Shape up male kiwis after they flower in summer.
Harvesting Kiwi Fruits
Growing kiwis is a time investment. It may take 2 to 5 years to see a plentiful harvest. Look for the fruits to begin to ripen in early fall. Semi-tropical kiwis are ready to pick when the skins turn brown, but the fruit is still firm. You can further test for ripeness by slicing into one of the fruits. If the seeds are black, go ahead and harvest the rest. Give them about a week at room temperature to soften before eating. Hardy and semi-hardy kiwis will drop from the vine when ready. To keep kiwis longer, put them in the refrigerator while they are still hard. They will stay fresh for 5 weeks to several months.