There are two main types of kiwi. Actinidia arguta (the hardy kiwi) and Actinidia deliciosa (the fuzzy kiwi). In general, both types require two plants,a male and a female, for pollination. Both plants produce flowers, but only the female will produce fruit. To insure fruit production, plant a male and a female of the same species. There are self fertile varieties of each species which yield smaller fruits.
A.arguta has small, smooth skinned fruit and can withstand -35 C ( –25 F). Fruits of the hardy kiwi can ripen on the vine in late fall.
A. deliciosa has larger, brown, fuzzy fruits and can withstand -12.2 C to -9.4 C (10-15 F) (they can survive -17 C (0 F) with freezing damage).
Growing conditions
The first years of establishing a strong root system are critical to kiwi grower’s success. Three important elements include a warm root system, soil nutrients and ample water.
A site that is full sun with well drained soil that is rich in organic matter is ideal for kiwi growth.. The leaves may show nitrogen deficiency if the soil is too basic.
The plants do not tolerate salty soils. It will tolerate some shade but prefer a sunny location where they can ramble across some type of trellising system. They should have some protection from strong winds.
Watering Kiwi fruit plants need large volumes of water during the entire growing season but must also be in well-drained soils. Watering regularly in the heat of the summer is a must. Never allow a plant to undergo drought stress. Symptoms of drought stress are drooping leaves, browning of the leaves around the edges, and complete defoliation with regrowth of new shoots when the stress is continuous.
Fertilization Plants are heavy nitrogen feeders which should be applied in abundance during the first half of the growing season. Late season applications of nitrogen will enhance fruit size but are discouraged as the fruit then tends to store poorly. In basic soils, a citrus and avocado tree fertilizer should be broadcast about the vine and watered in well in early March. Follow up the initial fertilizing by supplemental additions to early summer. Mulching with manures and/or straws is very beneficial. However, do not put the mulch directly in contact with the vine as crown rot will occur.
Planting
1. When ready to plant, dig a hole large enough to accommodate the roots without crowding. Slow acting materials like rock phosphate, kelp meal, and compost can be mixed with the soil in the planting hole.
2. Potted plants should be planted carefully so as not to disturb the roots. Root bound
potted plants however should have their roots pulled apart to some extent spread to the sides of the hole. For all plants DO NOT LET THE ROOTS DRY OUT. Kiwis should be planted at about the same level as they were grown in the nursery. After planting, soak the planting area to remove air from around the roots.
3. Vines should be planted 3.5m (10 feet) apart or trained to grow in opposite directions. The male and female plants can be a maximum of 10.7m (35 feet) apart for pollination. The flowers are pollinated by bees, yet they do not offer nectar for attraction. Therefore, it is best to cut competing flowers around the vines when kiwis are in flower.
Water regularly and deeply for the first year, especially during dry periods. Adding mulch annually to reduces weeds and preserves moisture. If needed, use an insecticide soap during the growing season to control insect pests. Train kiwi vines to a sturdy fence or trellis for best results.
Flowers and Pollination
Kiwi is a dioecious plant: male and female flowers are produced on separate plants. To cross-pollinate, intersperse male vines with the female fruit-producing vines. Pollen from one male vine can pollinate up to eight surrounding female vines. Male vines flower profusely, but do not produce fruit. Numerous stamens-the pollen producing structures-and lack of styles-the pollen receptors-characterize male flowers. Female flowers have just the opposite characteristics. Honey bees pollinate kiwis. Open flower clusters are not very attractive to bees; a shortage of bee activity results in small, misshapen fruit.
Note: Vines do not begin to bear fruit until they have grown for 4 years. They fruit on the previous year’s wood and can produce up to 100kg of fruit per plant.
Harvesting
Actinidia arguta (hardy)- drop or come off easily when they are ripe. Usually they are picked at the mature-ripe stage and allowed to ripen off of the vine as is done with kiwifruit. The fruit are generally green, fuzz free, and the size of grapes. Cut open, they look much like regular kiwifruit with its small black seeds, emerald green color, and typical rayed pattern. Although typically green in both the skin and flesh, some cultivars have various amount of red, either in the skin, flesh or both. Hardy kiwifruits are generally sweeter than regular kiwifruit.
Actinidia deliciosa (Fuzzy)- Best to wait for harvest until at least November 1, but November 15 would be preferable. Seed inside should be fully black by this time. Once harvested, place the hard fruit into plastic bags and put into the refrigerator for keeping. When needed, the fruit can be taken out of the refrigerator and ripened on the counter for a few days in a plastic bag. Well stored fruit can last for several months. The oval, ovoid or oblong fruit is up to 6.6cm (2-1/2 inches) long, with russet-brown skin densely covered with short, stiff brown hairs. The flesh, firm until fully ripe, is glistening, bright green or sometimes yellow, brownish or off-white, except for the white, succulent center from which radiate many fine, pale lines. Between these lines are scattered minute dark-purple or nearly black seeds, unnoticeable in eating. The flavor is sweet/tart to acid, somewhat like that of the gooseberry with a suggestion of strawberry.
General Pruning Care
When planting cut the plant back to about 30cm (1 ft) from the ground.
Select a vigorous shoot to grow rapidly to the top of the support. Gently tie this shoot to a stout post as it grows, and later remove other less vigorous shoots. When the vine reaches the top of the support, tip it back,allow two buds near the top to grow; train them along the support wires or beams. Tie them loosely with heavy string or plastic tape. These cordons form the basic structure of your plant.
A-Prune to one or two buds at planting.
B-Train one shoot as trunk remove all others (year 1)
C-Head back trunk as shoot growth at terminal loses vigor.
D-Continue to remove lateral shoots, let trunk grow beyond wire. Then head to just below wire.
Plan a major annual pruning session in the winter around the first week of February with the goal of cutting away excess growth and shaping to develop a strong main trunk. Cut back vines to the point where they have three or four buds but not further as Kiwi blooms on last year’s wood.
E- Choose two shoots to form cordons, one each way on wire. Head back to 1/4 inch diameter wood in dormant season.(year 1)
F- Shows shoot growth year 2 cuts in dormant season year 2 are shown.
Prune back lateral vines that grow from the main trunk down to the trunk joint every two to three years. These are the main fruiting vines, so do not prune them all at once but on a rolling schedule, balancing cuts on both sides of the main trunk. Re-tie the vines as needed to stabilize.
Prune non-fruiting male vines immediately after flowering. Cut the flowering arms down to between 43.18cm (17in) and 66cm (26 inches) in length so that mostly new green growth remains.
Conduct maintenance pruning with your secateurs to control shape and size, prevent tangling and allow for light and air penetration into the body of the plant. Make fresh tiebacks from the vine to the climbing structure as needed to support the cutback vines.
Pests and Disease
Kiwi fruit plants are relatively free from problems. One odd problem is the fact that the trunks have a catnip-like aroma which cats love to rub against. When plants are small, this can be a problem as they can rub off any new shoots which emerge in the spring. Garden snails can also be a problem on younger plantings. Other pests include deer browsing on the leaves and gophers attacking the roots. Scale insects can also be a problem if populations build up too extensively.
Where present, root-rot nematodes will reduce plant vigor.
