Plant, care and harvest Japanese grapes

The Japanese grapeberry is closely related to raspberries and blackberries. We introduce the Asian treasure and give tips on cultivation, care and use.

The exotic Japanese grape berries can also be cultivated here in spite of their Far Eastern origins and bears tasty fruits. In this article you will learn everything about the choice of variety, cultivation, care and harvest time of Japanese grapes.

Japanese grape: origin and characteristics

The Japanese grape (Rubus phoenicolasius) belongs to the rose family (Rosaceae) and to the genus Rubus. The species name phoenicolasius is made up of the parts

Phoenix (= purple-red, fox-red) and lasios (= densely hairy, shaggy) and alludes to the hairiness of the shoots. The Japanese grape is close with blackberry (Rubus fruticosus) and raspberry (Rubus idaeus) related. Some sources name the Japanese grape berry as a hybrid between blackberry and raspberry, comparable to Loganberry or Tayberry. However, this crossing should have taken place naturally, i.e. without human intervention. As the name suggests, Japanese grapes are found in Japan, but are also native to Korea and China. Since the end of the 19th Century it is used by humans and since the second half of the 20th Century also cultivated in this country. The Japanese grapeberry is also known as blackberry, Japanese raspberry or red-bristled raspberry.

It grows as a rampant 2-3 meter high and equally wide, upright and deciduous shrub with overhanging or prostrate side shoots. There are only a few thin spines on the red-brown rods. Instead, the shoots are dense and bristly covered with red glandular hairs, which gives the plant an exotic, but also extremely elegant appearance. The dark green, three to five-fold leaves are about 10 centimeters long and are flocked white on the underside. The Japanese grape, like its relatives, forms root runners and can spread so well. Old plants can take up a space of 16-20 m². The pale pink flowers of the Japanese grapevine are in small clusters. The flowering period extends from June to July. The flower buds, just like the shoots, are red in color and have sticky, bristly hairs. The initially apricot-colored, hemispherical aggregate drupes ripen from July to August, then turn a deep wine-red color and feel slightly sticky.

Planting Japanese grapes

For domestic cultivation there is no subdivision of the Japanese grapevine into varieties, as a rare exotic berry it has probably not been cultivated until now. Sometimes it is called a hybrid berry or under Blackberry varieties Strictly speaking, however, the Japanese grapeberry is a species of its own. Japanese grapes aren't picky about their location as long as it's a little sheltered and warm. Similar to blackberries, they grow on all types of soil as long as no waterlogging occurs. The ideal location for Japanese grapes is sunny to partially shaded on well moisture-retaining, moderately nutrient-rich soils with a calcareous to neutral pH value. Either you let the vigorous bushes grow wild or you guide the Japanese grapes on climbing aids or trellises along walls and fences. You can also let it grow as a fruit-bearing hedge.

The Japanese grapevine is planted in the spring after the ice saints, as the young plants are in the are still a bit sensitive to frost in the first few years and the hardly rooted plants are damaged can. So it can form strong roots by the first winter and already establish itself somewhat. Before planting, the soil should be enriched with organic material, such as ripe compost, and large areas should be dug up. Individual Japanese grapes should be placed at a distance of 150 cm from each other so that they can develop well. When planting, dig a deep hole and place the Japanese grapevine in it so that it is about 10 cm deeper than before. The shoot buds on the root neck are covered by soil and can develop well.

When planting grapes in pots, the planter should hold at least 10-15 liters and the shrub should be moved to a larger container every year. For planting in pots, we recommend a nutrient-rich potting soil like ours Plantura organic universal soil. It provides young plants with a basic supply of all essential nutrients and, thanks to the high compost content, promotes root growth and soil life.

tip: To prevent Japanese grapes from spreading too much in the garden, you should use a root barrier about 40 cm deep when planting. The flat roots only spread within the barrier by means of the root runners.

Summary: Planting Japanese grapes

• Location: sunny to partially shaded
• Soil: Retains moisture, moderately rich in nutrients, contains lime to neutral pH
• Planting time: After the ice saints
• Plant spacing: 150 cm

The most important maintenance measures

The Japanese grapevine is extremely easy to care for, because once it has established itself in the garden, only a few points need to be considered. Shrubs that are still young and fairly freshly planted should be used in dry summers Gmust be watered, otherwise the fruiting will stop and rods can die.

In spring, the nutrients that have been withdrawn over the year should be replaced with ripe compost or a long-term fertilizer such as ours Plantura organic universal fertilizer be freshened up. The fertilizer granulate is worked into the surface around the berry bush and decomposes over it For months, the nutrients contained are only available to the plants slowly and without the risk of leaching power. Another maintenance measure is the cutting of the Japanese grape berries. The Japanese grape bears on last year's shoot. Worn rods die off after the harvest. For this reason, old, harvested and dry shoots are removed near the ground every autumn.

Are the Japanese grapes hardy?

As an adult plant, the Japanese grapevine is completely hardy. Young plants outdoors should be protected from severe sub-zero temperatures with brushwood or fleece in the first two years of standing. Plants in pots should not be left unprotected outdoors in winter, because there is a risk that the root ball will freeze through and cause great damage to the plant. Therefore, Japanese grapes should be wintered in pots frost-free at around 5 ° C and light in the shed or garden shed.

Propagate Japanese grapes 

Japanese grapes can be grown vegetatively using runners or cuttings, but also reproduce generatively via their seeds. However, growing seedlings from the seeds of the Japanese grape berry is no easy task. First of all, the pulp around the seeds has to be detached from the wet and cold. The seeds are Cold germ, therefore need a long-term cold stimulus in order to be able to germinate at all. After the cold treatment, which lasts 4-6 weeks, the seeds are spread out on the surface of the growing medium and only lightly pressed. This is necessary because they are also light germs that need brightness to trigger germination. At around 15-18 ° C and high humidity, germination takes around 2-4 weeks. After another four weeks, the tender young plants can be moved for the first time.

The numerous root runners of the plant are ideal for propagating the Japanese grape berries much faster and easier. They can be cut off from the mother plant with a spade in autumn or spring, dug up and moved to a new location. Even cut, about 15 cm long shoot cuttings usually take root quickly in moist soil and quickly form independent plants. Another alternative are the mostly naturally formed lowerers. This creates roots on shoots lying on the ground when they come into contact with the earth. If the sinker is already well rooted, you can use secateurs to cut the connection between the rod and the mother plant, dig up the sinker and move it.

Harvesting Japanese grapes: when and how to do it

The deep red, slightly sticky fruits of the Japanese grape are harvested between July and the beginning of September. When fully ripe, the collection drupes, just like raspberries, detach themselves from the stalk well and easily and can be collected.

tip: Maggots and many other pests avoid Japanese grapes, so you can harvest and enjoy the fruit without hesitation. It is believed that the sticky bristle hairs on the shoots and calyxes are responsible for many of the typical raspberry pests, such as the raspberry beetle (Byturus tomentosus), keep away.

The taste, ingredients and uses of Japanese grapes 

The taste of ripe Japanese grapes is sweet, aromatic and pleasantly refreshingly sour and wine-like. It is ideal for snacking directly from the bush. However, the fruits cannot be stored and must therefore be processed immediately after harvest.

True delicacies are grapes dipped in chocolate, homemade jam or jam made from Japanese grapes, and fruit wine. Basically, all types of preparation of raspberries or blackberries, such as juice, chutney or liqueur, can also be converted into recipes for Japanese grapes. Due to its high mineral content, the Japanese grapeberry is very healthy and scores above all with its high vitamin A and C content.

Among the raspberry-like fruits there is also a diverse one Salmonberry. We present the little-known plant and its best varieties for growing in your own garden.