kiwi fruit: tips from planting to care and harvesting

 The kiwi has long since established itself in the garden in this country as well. We give tips from planting to care and harvesting.

Origin

The kiwi (Actinidia) belongs to the family of the ray pens (Actinidiaceae). 

Although the fruits are mostly imported from New Zealand, 

they originally come from China. This is also where its actual name "Chinese gooseberry" comes from. 

The name "Kiwi", which reminds of the heraldic animal of New Zealand, 

the small bird, was created for marketing purposes. 

The kiwi has been known for 30 years and has been one of the most popular exotic fruits ever since.

To the type of the kiwis, different types belong, that are called however usually simply kiwi. 

The most widespread are the large hairy kiwis (Actinidia deliciosa), 

the somewhat less acidic, smooth-skinned Actinidia chinensis with yellow flesh, and the kiwi berries, 

also called mini-kiwi (Actinidia arguta). Kiwis have been cultivated 

in Asia for over 1,000 years - not least because of their long shoots, which were used for paper production. 

The fruit, which requires warmth and is sensitive to frost, can also be cultivated here, 

but the cultivation of the large-fruited kiwis is only recommended in 

wine-growing regions and in locations with mild winters and rainy summers. 

As an ornamental plant, the colorful ray pistil (Actinidia kolomikta) is popular.

Appearance and growth

Kiwis are perennial, liana-like growing, deciduous creeping plants. 

The large, wheel-shaped flowers of the kiwi plant appear from June to July. 

Its flowers have snow-white and later yellowish petals with numerous golden-yellow stamens. 

Except for a few new varieties, the plants are dioecious, so they bear either purely 

male or purely female flowers. 

By the shape of the flowers you can distinguish male from female flowers: 

Numerous stamens and small pistil mark male flowers, 

while female flowers appear in small numbers per inflorescence and carry 

radiating white pistil-like arranged pistils, which are surrounded by a wreath of stamens. 

The fruits develop only from the female flowers.

The fruits of the kiwi are large, depending on the variety, 

cylindrical berries covered by a brown and densely hairy skin. 

Inside the fruit there are many intergrown seed containers with black seeds along the central axis. 

The flesh is green and soft. It tastes sourish, aromatic, especially when the fruits are fully ripe, 

but not overripe. Kiwis have a high vitamin C content. 

Since the plants twine like lianas in height and width, they need a climbing aid along which they can grow.

Location and soil

Kiwis have a low frost resistance and the sprouting is very sensitive to late frost. 

Even in warm regions or wine-growing areas, kiwis therefore thrive best in a place sheltered from the wind. 

The location must be warm and bright, but not full sun. 

In locations outside fruit and wine growing areas, place the kiwi plants against 

a southwest wall or on the west side of the house. In this way you can delay 

budding in spring until the danger of late frost has passed. 

A loose, nutrient- and humus-rich soil with a pH value in the slightly acidic range is best suited. 

The kiwi does not tolerate calcareous soils very well. 

If necessary, some rhododendron earth can be added to the soil. 

Soils that are too poor should be improved in advance with compost. 

Kiwi plants are also suitable for large plant pots on the terrace.

Plantation

Since kiwi plants grown from seeds only flower after six to ten years, 

it is advisable to buy young plants from a specialist shop. 

These were usually propagated by cuttings and thus flower after only two to four years.

The kiwi is prone to late frost - the ideal planting time is therefore from mid-May to August. 

Since kiwis are dioecious, they should always plant male and female plants to ensure fertilization. 

The optimal planting distance is three to four meters. 

It is recommended to work as much leaf or bark compost as possible into the soil 

as preparation and to water the young plants well afterwards. 

It is also advisable to apply a layer of mulch to the soil immediately after planting. 

This ensures that the soil does not dry out as quickly and does not heat up as quickly in dry periods. 

For the tendrils of the kiwi plants, which can grow up to ten meters long, 

a stable climbing frame, such as a pergola or trellis (see "Upbringing and pruning"), is necessary.

Care tips

In order for the fruits to ripen and develop their aromatic and sour sweetness, 

kiwis must be watered regularly, especially in hot summers. 

You do not need to fertilize young plants. Older plants can be provided 

with horn meal or mineral fertilizer in August and spring. 

During the first few years, you should also cover the stems and root area of the kiwi plants with brushwood in winter. 

If you keep kiwis in a pot, a sufficient supply of water and nutrients is essential. 

You should also regularly trim shoots that are too long.

Education and editing

Since the kiwi develops long shoots, the plant needs a stable climbing frame. 

A trellis framework with two to three horizontally tensioned wires is recommended. 

If the plants are pulled against the house wall, 

you can build this simple scaffold directly in front of it and tie the shoots to it. 

The lowest wire should be about 80 centimeters high, the next ones at 50 centimeter intervals.

Also suitable as scaffolding are arbours or pergolas to which the side shoots of the kiwi plants are attached. 

In the first years, one main shoot should be pulled vertically from the trunk to the top wire. 

From this main shoot, two strong side arms are then pulled horizontally to the left 

and right and the fruit-bearing branches are placed over the wires. 

Over the years, the liana-like growing plants thus become denser over the trellis 

or pergola and offer a nice visual cover. 

An additional advantage is that large-fruited kiwis can hang there for a long time in autumn. 

Cutting the kiwi is necessary from around the third year of growth. 

The annual fruit shoots can be shortened by about a third in August, leaving about six to eight leaves. 

You can also shorten the ends of the leading shoots once a year. 

Cut back more in late summer, as the plants bleed heavily in spring.

Fertilization

Most kiwi varieties are dioecious. This means that each plant bears either only female or only male flowers. 

Therefore, at least one male and one female kiwi plant are required for fertilization. 

Neglecting this point is one of the three biggest mistakes in kiwi cultivation. 

One male plant can fertilise up to seven female plants if the planting 

distance is not too far apart (preferably not more than four metres).

There are now also a few monoecious kiwi varieties that have male and female flowers on one plant. 

Theoretically, they can do without a pollinator variety. 

However, practice shows that the fruit set of these varieties is also much higher 

when two plants are placed next to each other. 

If bees, bumblebees and other insects fail to appear at flowering time, pollination should be done by the plant itself. 

To do this, carefully stroke the stamens of a male flower over the ray-shaped white pen in the middle of the female flowers.

Harvest and utilization

Kiwis contain a lot of vitamin C and are rich in calcium, iron, potassium, other 

minerals as well as vitamin B1 and E. The fruits are also rich in fiber and low in calories. 

The kiwi harvest takes place from the end of September until October. 

Since they often do not ripen completely in cooler locations on the plant, 

the fruits can be simply left to ripen indoors on the windowsill. 

Unfortunately, kiwis that are ready to be harvested do not keep for too long. 

However, they can be stored quite well in a humid room at a temperature of 12 degrees Celsius. 

You can eat the vitamin-rich kiwis fresh, 

but you can also process them into jams and jellies, 

boil them down or use them for cakes, such as green tea cakes with kiwi, or bowls.

Hibernation

Although most kiwi varieties are hardy, winter protection is always advisable in the first winter for young, 

freshly planted seedlings. A warming ground cover of bark mulch and 

fir brushwood are ideal as wind and sun protection for the shoots.

If kiwis are cultivated in a tub, they should be placed in a cool, 

bright location in the house throughout the winter because of their frost-sensitive roots. 

The plant is brought outdoors again when the shoots begin to sprout in March. 

Tips on varieties

Hayward' is a proven variety with large, hairy fruits. 

Its kiwis can grow up to seven centimeters long and weigh about 100 grams. 

They should be harvested after the first light frosts at the latest. 

The plants bear from about the fourth year of growth and need a pollinator because they are dioecious. 

The male variety 'Atlas' is suitable for this.

Equally popular are 'Bruno' with narrow and cylindrical fruits and 'Monty'. 

Abbott' grows strongly, blooms early and is an all-female variety. 

From the end of October, its cylindrical, medium-sized fruits are ripe and have a very sweet taste. 

Matua and Nostino are male pollinators.

The plant can tolerate brief sub-zero temperatures even without frost protection.

The kiwi variety 'Jenny' is a very high-yielding and self-pollinating variety. 

Its fruits are up to four centimeters long and smaller than those of 'Hayward', weighing about 20 grams. 

The very sweet, juicy fruits are ready for harvest from mid-October. 

They usually ripen on the shrub in the winegrowing climate, in climatically less favorable locations they are left to ripen indoors. 

Tip: 'Jenny' is also suitable as a fertiliser for large-fruited dioecious kiwi varieties such as 'Hayward'. But: Even if she is a self-pollinating variety, she will carry more weight if she is planted with a male partner. 

Mini kiwis are descended from the wild species Actinidia arguta. 

They are harder on frost and require less heat than large-fruited varieties. 

The high-yielding plants form smooth-skinned fruits that can be eaten unpeeled directly from the shrub. 

A proven variety is, for example, 'Weiki', which was bred at the Weihenstephan 

Research Institute and is therefore also called "Bavarian Kiwi". 

Like the well-known male variety 'Kiwai', it is the result of selections from Actinidia 

arguta and Actinidia melanandra. Weiki' produces walnut-sized, sweet fruits rich in vitamin C, 

which ripen from the end of September onwards. 

It is resistant to pests and plant diseases and yields up to 30 kg. 

A male variety is required to fertilise the flowers. 

The 'Issai' variety is a self-fertilizing mini kiwi. 

The fast-growing climbing shrub can grow up to 18 meters high and is extremely frost hardy. 

The yield starts after two to three years. 

Its smooth-skinned, green fruits grow up to four centimeters long, 

taste very sweet and develop a pleasant aroma.

Reproduction

Kiwi plants are propagated by cuttings. 

For this purpose, cut in early summer about 15 centimeters long, 

at least pencil-thick shoots with already lignified bark and three to four clearly recognizable eyes. 

Remove all leaves except a few at the shoot tip and put the cuttings into pots filled with lean growing soil. 

Lower the pots into the soil in a shady, wind-protected place and cover the surface 

with a thick layer of straw mulch. Once the cuttings have rooted through the pot, plant them in the designated place.

Diseases and pests

Kiwi plants are generally very robust. Occasionally aphids or scale insects occur, more rarely fungal diseases.