In good conditions, long-lived kiwi vines could grow as much as 20 feet in one year. Maximum fruit production depends on proper pruning technique. Male and female kiwi plants require different types of shaping. In general, pruning kiwi vines follows the same rules as for pruning grapes, since the plants fruit from canes already a year or more old.
Pruning Female Kiwi Vines
Each year remove all sucker shoots growing from below the grafted portion of the kiwi vine. In winter, remove any damaged branches. Trim back fruiting canes of mature vines to control excessive growth and prevent fruit from touching the ground.
Train first year kiwi vines to grow a single trunk as high as the central wire of the trellis. Support the leader with a stake--when the leader reaches the trellis cut the top of the vine back to a few inches below the wire. Select two strong canes to run horizontally in opposite directions on the center wire--kiwi trellises commonly use three or five wires in parallel on T-shaped supports about six feet high. In winter, cut the branch canes back to from 20 to 30 inches long. Tie the canes loosely to the wire with garden twine.
Train four new canes as side branches on each arm of the kiwi vine in the second year. Tie them loosely to grow across the trellis wires at 90 degree angles. Allow one cane at the end of each central branch to grow along the central wire. When the central branches grow another 20 to 30 inches, clip the leader cane just past the last bud. In winter, cut the side branches back enough to limit the number of fruiting buds past this season's flowers to from six to ten. Prune off all but two or three strong fruiting canes on the side branches.
Prune out new canes shading fruit clusters to hasten ripening in the third year. Train one cane at the end of each main arm to follow the central trellis wire outward. Clip the end of the cane to limit the length of the main branch to eight feet. Train four new canes as lateral branches from last year's wood on the central arms. Prune these new fruiting canes back, allowing 6 to 10 fruiting buds for next season. Cut off any 2-year-old fruiting canes after harvest and retain two or three new fruiting canes on the lateral branches.
Prune four year and older vines to keep the pattern of two eight foot main arms with about eight strong side branches on each arm. Limit fruiting canes to two or three per side branch. Thin out new canes to allow sunlight to reach ripening fruit. In winter, prune off the any fruiting canes that bore fruit for two or more years, saving new fruiting canes to replace them.