Actinidia arguta

National Arboretum #7 was a female kiwi growing on the R Street fence at the National Arboretum. It is no longer there but fruiting at the nursery. When visitors sample the different kiwis, many fine this one their favorites.

What Can't Kiwi Fruit Do?
In what is believed to be one of the first papers published from China on Kiwi, Liang Boo adds exciting new possibilities for this famous fruit. The fragrant flower is rich in nectar and also provides a good base for the production of perfume.

The leaves contain starch protein, vitamin C and various other nutrients and make good pig feed. On using kiwi fruit for herbal medicines, he says it has proved effective in reducing fever, improving urination, dispersing exbavastated blood, stimulates blood circulation, steeping up milk excreting in nursing mothers, and relieving inflammation.

In some places, nursing mothers drink the liquid from the boiled root, plus a sweetener to promote lactation. And sufferers from boils, contusions or sprains are often given mashed root for external application.

The roots can be processed into an insecticide which is especially effective in killing such insects as rape and tea caterpillars, rice borers, aphids, cabbage worms and paddy rollers.

The stalk of the kiwi is rich in glue, which is obtained simply by soaking it in water. The glue is used in construction materials, road paving, and a protective covering for walls. The glue is also an important ingredient in the manufacture of wax paper and Xuan paper, a high - quality paper used in traditional painting and calligraphy.

Hardy Kiwi
Hardy Kiwi is a new fruit. They are delightful to eat, sweet, with an unmistakable kiwi flavor. The plants are vigorous, hardy and not prone to disease and insect imbalance. They are dual purpose for landscape and nutrition, and the fruits keep well is storage. The vines are long lived. The Actinidia arguta at Dumbarton Oaks in Georgetown, Washington D.C.. were planted in 1920. The female vine fruits annually.

The fruits are not only used fresh, they can be dried, made into a sherbet and prepared in a variety of other ways. The hardy arguta fruit is smoothed skinned and green. It can be eaten whole. It's sugar content is very high. Test at the Virginia Research Station averaged 17.7 Brix. Tests of the store bought kiwis (A. deliciosa) averaged 13.2 brix.. To judge how sweet 17.7 brix is , grapes to be dried for raisins should have a reading of 18 brix. The fruits are about the size of a small plum. When eating the fruit, the seeds are almost undetectable.

The arguta prefer somewhat moist and rich soil. Under suitable conditions they grow rapidly, fruit abundantly and bear early in life. Arguta's will tolerate infertile soils, but will not tolerate flooding of soils of poor drainage. Once established they are very tough and adaptable. I have seen established vines in Rochester New Hampshire, Geneva New York, Washington D.C. and Virginia Beach Virginia. We have plants producing as far south as Miami. Argutas are excellent for covering walls, trellises, arbors, pergolas, tall stumps and the like. They can be grown over chicken coops and on chicken yard fences. They grow well in sun or shade.

Members of the genus Actinidia are natives of Eastern Asia. While several species are found in Japan, Manchuria and Korea. In the wild the vine intertwines through trees or grows in tangled masses in the open. They can reach a height of 40'.

Hardy Kiwis are alternate leafed. Their leaves in size and shape resemble the leaves of an apple tree. Flowers open in late May on new shoots grown from the previous season's spur growth. Spurs are short branches with close internodes of less than two inches as compared to the main vine which has 3" to 5" internodes. The flowers are small and white with a lily of the valley fragrance. Individual plants are dioecious (male and female flowers are produced on separate plants). The West's realization of this plant comes rather late. Where it naturalizes people have used it for many years. Distribution outside of its native habitat began around 1847. In the 1900's collections were secured in England, France, the U.S. & new Zealand.

Hardy Male Kiwi Blooms

Female Blooms on Hardy Kiwi

Female Fuzzy Kiwi Flower

Pollination
Since kiwi fruit is a dioecious plant, that is, it produces male and female flowers on separate vines, both a male and female vine are required for fruit production. For best pollination 1 male for every 5 females. Size of a fruit depends, not only on good growing conditions and pruning, but also on the number of seeds that have been fertilized. Kiwi fruit vines should be considered tender and drought - sensitive until they are well established. Hardy Kiwi are heavy producers. As much as 150 lbs of fruit can be obtained from one female plant.

Growing Instructions
When planting space the plants at least 10ft apart. Plant the vines 10-20ft apart in the row, depending on trellis type & cultivation technique (ie: tractor etc.) Rows are commonly shallow cultivated or mulched. The nutritional requirements of A. arguta have not been well researched, but general recommendations have evolved. Fertilizer should be minimal or none at all at planting. Keep grass & seeds away and do not let the plants dry out the first year.. On established plants apply fertilizer twice per year with approximately twice as much applied before new growth as is applied after fruit set in June. Increase the rate of 1/2 lb. on newly planted vines to three lbs per plant by the 3rd year. These larger amounts should be well distributed over the entire root system to prevent root injury. A. arguta has few pests. Arguta roots are fleshy and can be injured by nematodes. Fuzzy Kiwis are best planted in rows north to south to prevent sun damage on the trunk of the vine. Winter damage like this can injure the plant so that it has to re-sprout from the roots.

Build trellises before or soon after planting to accommodate the rapid growth of plants. These can be similar to grape trellises but must be strong., Posts should be 4" to 6" diameter to support plant and fruit weights and 8ft to 9ft long. A post should be set 2ft to 3ft deep to prevent winds from tipping the row over. Run 8 to 12 gauge wire, at 6ft high. The wire allows vines to grow with easy access to fruits hanging from the underside. Be sure the trellis is sturdy. A common failure is the construction of inadequate trellises for supporting the weight of heavy fruit crops. A "T" trellis can be made from this system, which provides more area for the vine.

Train the 1st years growth to go up a stake. Side shoots can be pinched terminally so only 1 or 2 vigorous stems reach the 6ft mark. These stems will be trunks in a few years. Train later growth along the wires to form permanent arms. Branching extends outward from these arms and supports spurs from which flowers and fruits develop. The vigorous A. arguta (Hardy Kiwi) requires special pruning practices, which includes both summer and winter pruning (but mostly summer). For summer pruning, rub off basal suckers and strong vertical growth when they are only a few inches long,.(You'll know the strong vertical growth - it clips along @ 2 ft per day). Waiting until unwanted shoots are several feet long before removing them results in unnecessary weakening of the plant. After a framework is established all the new growth coming from the arms can be pinched easily. The general rule of thumb is - pinch new 8" growth back to 4". That 4" will elongate again in a few weeks, pinch it back to 4" so in all there is 4" of growth from the first pinching and 4" from the second etc... this is how spurs are made. The objective of winter pruning is to balance fruit production with vegetative growth. Preferred limbs for removal are the three year old fruiting branches (those which have finished their third year of fruiting), damaged wood and the tortuously twining current years growth. Shorten the remaining current year's limbs from the permanent arms sufficiently so that when laden with fruit they will not touch the ground. Branches with short internodes (spurs). These will bear flowers and fruit and should not be removed. Kiwi fruits reach mature size by mid-summer, but they require the remaining season to develop their mature texture and flavor. Determine full maturity by picking a fruit, allowing it to soften for a few days and tasting it for favorable flavor. When suitably sweet and flavorful, pick all fruits and refrigerate them until a few days before they are needed. Removal from refrigeration initiates softening and the development of the kiwi's final sweetness and flavor. Kiwi may also be picked off the vine when they become soft for fresh eating. In favorable weather, the unpicked fruits will dry on the vine. Once permanent cordons are established, a kiwi vine must be pruned throughout its lifetime in order to maintain it's form, contain its size, and most importantly, maximize its fruit production By pruning to provide a constant turnover of fruiting laterals, this training system can be maintained and productive for 60 years or more. Male kiwi vines can be trained and pruned in the same manner as female vines.

Mature Hardy Kiwi Vines

Hardy Kiwi growing up a brick wall

Crown & Root Rot on Kiwis
Phytophthora crown and root rot causes the kiwi plant to develop poorly and can cause the plant to die. Infected plants have small chlorotic (yellow) leaves: the terminal growth may die back, or be stunted. The first signs of root stress is when young tender ends of new growth-wilt; blacken. Infected plants will suddenly collapse during hot weather. Decayed tissue is found at the soil line. The infection can be observed at the soil line by removing or peeling the tissues away from the trunk or primary roots. Newly infected areas will have brown streaks. Older infections will be entirely brown and extend high up the trunk and far down into the primary roots. Healthy tissue will have cream or white colored tissue and sometimes the green band or ring of the cambium layer is seen. Phytophthora fungi require water saturated soil to infect a plant. Some species of Phytophthora prefer warm soil in the fall and spring to spread. Other Phytophthora prefer cold water. Some seek feeder roots, others go to large roots and move up the trunk.

These conditions are most prevalent in heavy soils with poor drainage above impervious layers that are just below the surface and low areas in the field where surface and underground water collects. Frequently crown and root rot will occur where the irrigation emitter continually releases water near the base of the plant. So, never plant in wet soil locations.