Kiwifruits are easy to grow.
They grow in clusters like grapes. Each is about the size of an egg or smaller. They have firm flesh like a melon and flavor that is a blend of melon, banana, lime, and strawberry.
There are several kiwifruit varieties, some for growing in warm winter regions, some for growing in cool and cold winter regions. Some must be peeled before they are eaten others can be eaten whole peel and flesh in a bite or two.
Kiwifruits are vigorous growers. The sum of their training and maintenance is to keep the vines from tangling and knotting.
Kiwifruit are also called Chinese gooseberry.
Choosing the Right Kiwifruit Plant for Your Climate Zone
There are three types of kiwifruit with differing degrees of cold tolerance: fuzzy-skinned kiwi (Actinidia deliciosa) will grow in Zones 7 to 9 and is the least cold-tolerant (it is hardy to about 25°F) and two smooth-skinned kiwifruits, the first, called hardy kiwi (A. arguta) which is hardy to Zone 4, and the second called super-hardy kiwi (A. kolomikta) which is hardy to Zone 3. Choose the kiwifruit that can survive the winter cold where you live. If you are unsure, contact the Cooperative Extension Service nearest you or ask at a nearby garden center for the variety of kiwifruit that they stock.
Best Site for Growing Kiwifruit
- Grow kiwifruit in compost-rich loamy soil that is well-drained. Roots can grow to more than 4 feet deep; soil should be easily worked. A soil pH of 6.5 to 7.0 is optimal.
- Avoid planting kiwifruit in windy spots; wind can stress and even break vines.
- Avoid planting kiwifruit in low spots where cold air or frost can settle.
- A single kiwifruit vine will produce 22 to 33 pounds of fruit each year. Kiwifruits may take up to 7 years to reach full fruiting potential.
- Most kiwifruits are either male or female. A few are self-fertile.
- A female kiwifruit must be planted with a male or a self-fertile partner in order to produce fruit.
- One male kiwifruit will pollinate up to eight female vines. Plant several different male cultivars with female plants; this will ensure that at least one male plant is in bloom when the female plants are flowering.
- Wind and honeybees are common kiwifruit pollinators.
- ‘Jenny’ is the best-known self-fertile variety.
- Space kiwifruits 15 feet apart; space rows 15 feet apart.
- A kiwifruit vine can grow 10 to 15 tall and wide.
- Plant kiwifruits in early spring or in late fall during dormancy. Avoid planting kiwifruits in hot, dry summer conditions.
- Kiwifruit will grow best in a warm, sheltered spot that is south facing; avoid planting kiwifruit where frost can settle.
- Put a trellis in place before planting kiwifruit. See the section on Training.
- If you are planting non-self-fertile varieties, plant a male and female together in the same planting hole.
- Dig a hole 12 inches deep and wide or larger; wide enough to spread out the roots of the plant or plants you are placing in the hole.
- Set the plant in the hole at the same level it was growing in the nursery container; if you are planting a bare-root plant set it in the hole so that the soil level mark on the bare-root plant is level with the surrounding soil.
- Refill the hole with half native soil and half aged compost or commercial organic planting mix.
- Firm the soil in around the roots so that no air pockets are near the roots; gently water the soil so that it settles in tight around the roots.
- Feed the newly planted vine with a liquid phosphorus-rich starter fertilizer.
- Tie the stem of the plant into the trellis or training wires. See the section on Training.
- Kiwifruit is best trained upward on a trellis; this will help keep vines from tangling and shading one another. Tangled and shaded vines yield less fruit.
- Kiwifruit can be trained to multi-wire espalier (similar to the Kniffen system of training grapes) or T-post horizontal wires support.
Training Kiwifruit to a Wire Trellis Using the Kniffen System
- The simplest support method for backyard kiwifruit is called the two-arm or four-arm Kniffen system which is essentially a vertical wire trellis. Set two sturdy posts 15 feet apart then string two parallel wires between the posts at 18 inches and 36 inches above the ground (this is the four-arm Kniffen), or you can use a six arms or eight arms by placing additional wires at 52 and 70 inches above the ground (do not train vines higher than it is convenient to harvest fruit). Plant young kiwifruit under the wire at 10 to 15-foot intervals.
- Tie the main stem or strongest shoot to the first wire and to the second wire if it is long enough. This will form the trunk of the plant.
- Next, choose side shoots or laterals to creep in each direction on the wire. Tie the side shoots to the wire with elastic horticultural tape; as the canes grow spiral them around the wire. These trained lateral canes are called “arms”.
- When the trunk reaches the second wire choose two more side shoots and tie them to the wire.
- Remove the growing tip of the trunk when it about 6 inches below the top wire and choose two more shoots to tie into the top wire.
- This training will create a tall main trunk with sets of selective side shoots or laterals which is important for growing the best quality kiwifruits. See Pruning below for more on this.
Training Kiwifruit to a Horizontal Trellis
- Kiwifruit vines can be trained to wires supported by T-posts; the wires run horizontal to the ground.
- Make T-posts to set every 15 feet. Bolt 2 x 4 cross-arms to 4 x 4 or 6 x 6 posts; the post should be 8 to 9 feet long (or less) allowing 2½ to 3 feet of the post to be buried in the ground. Stretch 3 to 5 horizontal wires between the posts; stretch wires to 300 pounds of tension—kiwifruit vines will become heavy with fruit.
- Plant a kiwifruit midway between two T-posts; put a stake in place to support the main stem of the vine. Attach the main stem and its laterals to the horizontal wire. Train the vines along the wires.
- Kiwifruit vines are heavier than grape vines; the supports must be well anchored.
Maintenance Pruning Kiwifruit
- Prune only when vines are dormant; pruning after buds begin to swell in spring can cause excessive sap flow which can weaken the vine.
- Cut the vines that form the lateral arms back to about 7 feet each winter.
- Remove 3-year-old fruiting canes at the end of harvest to make way for new canes that will grow next season. Lateral canes produce fruit for just three years; three-year-old canes must be removed to make way for younger fruiting canes.
- Several times during the growing season pinch away any shoots that grow from the main trunk
Container Growing Kiwifruit
- Kiwifruit can be grown in a container. Choose a container at least 18 inches wide and deep; larger is better.
- A trellis will be needed to support the vines. Make sure the trellis is well supported so that it does not tip over when vines are loaded with fruit.
Kiwifruit Care, Nutrients, and Water
- Keep the soil evenly moist throughout the growing season; if the soil goes dry during the growing season fruit may drop.
- Water sparingly in autumn as winter approaches; this will help vines adapt to cooler temperatures.
- Mulch to conserve soil moisture and reduce weeds. Mulch with aged compost or commercial organic planting mix to feed vines.
- Apply a balanced fertilizer in early spring as growth starts. Feed vines with compost tea or a dilute solution of fish emulsion or kelp meal during the growing season.
- Protect kiwifruits from frost by covering plants with plant blankets or burlap.
- Kiwi trunks are prone to winter injury; wrap them in burlap in fall.
Harvest and Storing Kiwifruit
- The kiwifruit is full-sized midsummer but it is not ready for harvest; it must stay on the vine to gain flavor and texture. Harvest usually comes in fall.
- Kiwifruit is ripe when the skin turns from greenish to fully brown and seeds are black; the fruit may still be firm.
- To test for flavor, pick a fruit, let it soften for a few days then taste it; if it’s sweet pick all the fruit and refrigerate it.
- Fruit can be harvested hard and allowed to further ripen and soften at room temperature. To speed ripening put firm fruits in a paper bag with an apple
- Kiwifruit picked too early will be tart; picked too late it will not store well.
- Cut the fruit off the vine with a small piece of stem attached; fruits with some stem attached will keep longer.
- Kiwifruits will keep in cold storage for up to 6 months.
- Fuzzy kiwifruits should be peeled before eating.
- Eat kiwifruits fresh or preserve by canning or drying.
- Fully ripe fruit can be frozen in slices for up to six months; thawed slices retain their texture and color but lose some sweetness.
- Kiwifruit can be blended with bland juices or drink by itself. Add fresh kiwi to salads, ice cream, cakes, mix with yogurt, even add to sandwiches; it is too delicate to cook.
- Pick all fruit before frost; if frost is not a danger, fruit can remain on the vine throughout the dormant season.
Kiwifruit Problems and Control
- Kiwifruits planted in well-drained soil have few pest and disease problems.
- Cats may like to roll in kiwifruit leaves or chew the vines; exclude cats with wire fencing.
- Drought and irregular watering or too little sunshine may cause leaves to fall and result in underdeveloped fruit.
Fall and Winter Kiwifruit Care
- Prune the vines every winter when they are dormant; remove about a third of the limbs growing from the permanent arms; remove limbs that have already fruited three years; remove damaged vines or twisted and tangled vines.
- Protect trunks from winter cold by wrapping them in burlap.
- The easiest way to propagate kiwifruit is by softwood cutting; take a 4 to 6 inch cutting of a new shoot; dip it in rooting hormone and set it in organic potting mix; cutting commonly root in 2 to 4 weeks.
- Kiwifruit seeds germinate readily after stratification—place seeds in the refrigerator for 3 weeks before sowing. The resulting plants will be either male or female.
- Kiwifruit can be propagated by grafting; use a dormant scion and join it to the rootstock in midwinter; use whip-and-tongue or cleft graft.
Kiwifruit Varieties to Grow
- Self-fertile cultivars: ‘Issai’, ‘Blake’.
- Cultivars with low chilling requirements: ‘Monty’, ‘Vincent’, ‘Abbot’, ‘Allison’.
- Female non-self-fertile cultivars: ‘Hayward’, ‘Bruno’.
- Male cultivar: ‘’Tomuri’
- Heavy crop producers: ‘Bruno’, ‘Abbot’.
- Produce fruit that can be eaten whole, including skin, like grapes: ‘Issai’, ‘Ananasnaya’.
Also of interest: