|I am finding conflicting/insufficient information on HARDY kiwi pruning: do they fruit on new growth off 1 yr. canes (like grapes)? on 1 yr. old growth (like single crop raspberries)? on new and 2 and 3 yr. canes (like currants)? What determines that a bud will be a fruiting cane or a vegetative only cane? Light? Temperature? Order in which emerged from dormancy? (I have seen all those specified, as well as finding some say prune sparingly and others say prune heavily. What's right??|
|According to "Flowering, Fruiting, and Foliage Vines", by Chuck and Barbara Crandall, kiwis fruit on the current season's growth.
One factor in whether a leaf bud or fruit bud forms is the relative levels of plant hormones. The levelsof these hormones are influenced by the force of gravity. That is one reason you train apple tree limbs to grow horizontally from the trunk. Besides providing a stronger anchor to the trunk, this horizontal positioning affects the plant hormones, encouraging the plant to produce relatively more fruiting spurs, and less foliage. Though I'm not sure it's the same with kiwis, I would suspect this is a factor.
This book suggests training kiwis to a "T" shape along a strong, horizontal wire for maximum fruit production. You train two strong, horizontal branches to these wires. Once they've reached the length you want, prune them there to encourage the growth of lateral branches. In early winter, prune these laterals back to leave six nodes. These will bear the fruits of the next season's crop.
In early summer, prune these lateral canes back to 5 to 10 buds. This will to create less vegetative growth and more fruiting spurs, resulting in more--and bigger--fruit. (Since the laterals bear fruit near their bases, you won't affect the crop.) Continue to pinch back to four inches any new growth or water sprouts more than eight inches long. Hardy kiwi are vigorous growers, so you'll probably need to pinch these shoots back three times over the course of the summer. Let the old growth and fruiting spurs develop normally. Pinching new growth redirects energy to this year's fruiting spurs, which can result in a 20% increase in fruit size. It also stimulates the plantto create more fruit spurs for next year.