Hardy Kiwi (cont)
By: Nan Sterman
How to Grow Hardy Kiwis
If you prefer to plant bare-root, buy and plant hardy kiwis in winter or early spring, when you would any other bare-root fruit. In cold-winter areas, plant after all chances of frost have passed, from spring until midsummer. In areas with long growing seasons, plant hardy kiwis anytime, but do avoid the hottest parts of summer, when transplant stress is high.
Hardy kiwis must have strong vertical support. In their native forests, these heavy vines climb trees. In a home garden, they require a sturdy structure such as a patio overhead or a trellis with 4-by-4 supports.
Kiwis are dioecious, meaning you need to grow male and female plants in order for the female plants to set fruit. A single male will pollinate at least eight females. Space plants about 12 feet apart. If space is limited, place both a male and a female plant in one planting hole, or grow (A. arguta) 'Issai', the only self-fertile variety.
For A. arguta, A. cordifolia, and A. purpurea, select a spot with good drainage and at least half a day of sun. A. kolomikta 'Arctic Beauty' requires at least half a day of shade.
Hardy kiwis need rich soil. Generally, about 10 pounds of compost or manure per plant, in both early and late spring, is enough. However, if growth seems to lag, or if leaves are pale, supplement with a pound of soy or cottonseed meal per plant in late spring or early summer.
Growers have different fertilization schemes. Roger Meyer, a commercial grower in southern California, applies half of his plants' yearly fertilizer allotment in late winter and the rest in monthly applications through July. Michael McConkey, who grows and sells hardy kiwi at his nursery in Virginia, fertilizes twice a year. He applies a third of each plant's yearly allotment before spring growth starts and the rest after fruit sets.
Pruning. Hardy kiwis are long-lived. Careful and rigorous pruning is essential to create strong and productive plants. In their native forests, these plants put most of their energy into climbing to reach the sunlight at the top of the trees. In your garden, however, you want them to direct that energy into making fruit. You need to prune often, once every few weeks during the growing season. As one grower notes, "You can't overprune a kiwi."
Your goal is to create an umbrella-shaped plant. In the first year, limit each plant to one vertical shoot, and direct that shoot to the top of its support. That shoot will become the plant's trunk. Wire or tie it loosely to the support.
In the first dormant season, prune each vine back to the top of its support.
In the second growing season, select two strong side branches near the top of the trellis and train them horizontally along the support. In the second dormant season, prune the side branches back to 1 to 2 feet long (12 to 18 buds on each). New branches will sprout from these side branches and become next year's fruiting wood.
From the third year on, prune female kiwis in the dormant season so that fruiting branches are at least 6 inches apart along the main branches. Cut out any dead or weak wood, and all tangled branches. Cut off branches that reach the ground or are so close that their fruit clusters could reach the ground.
In cooler areas, prune males back hard in summer. Prune as often as necessary thereafter to keep them tidy and to prevent them from overtaking the female vines. Restrict pruning to spring and fall in hot climates because bare branches are susceptible to sunburn. Whenever you prune, be sure to leave some of the previous year's wood so the plants flower and produce pollen.
Vines have a tendency to bleed if pruned too late in the dormant season, so do dormant pruning in the dead of winter.