Sophora japonica is a specialty in domestic parks and avenues, where it has been successfully cultivated since the mid-18th century. Due to its late blossoming, the tree offers numerous insects a rich source of food even in late summer. In addition, the Japanese ornamental tree retains its complete foliage well into autumn. The plant requires little care, but the space requirement is all the more lavish.
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location and soil
Few deciduous trees can cope with dark places in the shade without suffering weaknesses in growth and resilience. The Japanese cord tree is also one of the ornamental plants that prefer a full sun to light location in the partial shade. Sophora japonica are sensitive to waterlogging. A humus-rich, permeable soil is necessary for the successful care of the tree. The pH value of the substrate may be neutral to basic, even a high proportion of lime does not damage the tree.
watering and fertilizing
With increasing age, Japanese cord trees develop a widely branched, flat root network. Nutrients and moisture are taken directly from the soil and utilized via this. On hot summer days, when the soil dries up over a large area, you should water the ornamental tree every day. Water in the evening or in the morning so that the moisture does not evaporate through the sun but can reach the plant roots in a targeted manner. Young plants, on the other hand, should be continuously supplied with water during the growing season. Create a watering rim when planting so that the precious water can drain more easily into the ground.
Mulch the soil around the Japanese patrician tree regularly and mix compost into the substrate in spring and late summer. This supply of nutrients is completely sufficient with normal garden soil. Poor soil can also be upgraded with a monthly dose of liquid fertilizer.
The cultivation of seeds is tedious, but possible. For successful germination, the seeds of Sophora japonica must experience a cold phase. The seed pot should remain outdoors, sowing takes place immediately after ripening in October or November. It can take 3 months for germination, only then do the young plants need a substrate rich in humus. In the first three years of life, the plants are extremely sensitive to cold. Slowly get the seedlings used to the UV radiation outdoors in spring and move the plants to a cool, frost-protected room from mid-September. A greenhouse is also an option for the young plants. Incidentally, snails like to eat the small plants, apply slug pellets or otherwise protect the young cord trees from the voracious garden dwellers.
The ornamental trees from Asia do not flower until they are 12 years old at the earliest. In order to enjoy the flowering faster, you can also propagate the ornamental trees via “grafting”. This preserves the individual characteristics of the Japanese cord tree and you can influence the size and growth habit of the new garden dweller right from the start. The mourning cord tree, for example, can only be propagated using this measure.
Sophora japonica are tall, imposing deciduous trees. The lush crown of the ornamental tree, which grows up to 25 meters high, can reach a circumference of around 15 meters. The Japanese cord tree is therefore not suitable for small gardens or green spaces. The plant unfolds its full splendor in extensive parks and gardens. The widely branched, shallow root system exerts immense pressure on underground pipes. If you have the optimal location, nothing stands in the way of successfully planting a cord tree in your own garden.
The root ball of the plant should be able to soak up moisture about 6 hours before moving outdoors. A bucket filled with lukewarm water is sufficient for this. Meanwhile, prepare the planting hole and the excavation. The hole should be at least twice the width and depth of the tree’s root ball. Humus is added to the substrate, coarse pebbles are also helpful in particularly loamy soils. This loosens the soil and prevents waterlogging.
The tree must be planted all the way to the root, gently press down the backfilled soil and water heavily. Newly planted trees need to be watered daily for the first 14-21 days. This accelerates the acclimatization of the plant. Because the roots first have to be firmly rooted in the ground before they can independently absorb moisture from the soil. The large tree grows very slowly in the first few years and reaches a maximum growth height of 20 centimeters per year.
Older trees are hardy and can withstand double-digit temperatures well below -20°C. However, before the cord trees achieve this frost resistance, it sometimes takes four to five years. Protect young Sophora japonicas with a thick layer of mulch or foliage. Wrapping the trunk in sacking has also proven effective, but it is primarily the roots that are sensitive to sub-zero temperatures. Young trees should spend the first few years in tubs so that you can move the plants to a light and sheltered spot before the first frost. The ambient temperature should be around 10°C during the winter.
The imposing trees from Asia only blossom in summer. The foliage stays on the branches for a correspondingly long time. In spring, however, the Japanese cord tree is one of the last deciduous trees to sprout its buds. No pruning is allowed during this time, as the plant is “in the sap” and could bleed heavily as a result of this action. Only deadwood and diseased branches should be removed in late summer. Cross-growing shoots or those that disturb the tree’s appearance can also be removed with a sharp tool. Disinfect saws before and after work to avoid potential transmission of pathogens to other plants. However, unless absolutely necessary, you do not need to prune the Sophora japonica annually,
Useful care tips
Road salt – A Japanese tree is extremely sensitive to road salt. Therefore, do not plant the ornamental tree in the immediate vicinity of the road and avoid spreading the aggressive material on the garden paths even in winter.
Flowers – The butterfly-shaped inflorescences, which can reach a length of 20 centimetres, are an important food source for bees and other insects. The Japanese cord tree got its name from its fruits, which are reminiscent of pea pods. These are inedible and, if eaten, cause severe symptoms of poisoning in humans.
Planting tips – You can achieve romantic garden corners with Japanese hanging cord trees. The bizarrely shaped shoots of the tree offer the ideal privacy screen for arbors and at the same time serve as a fascinating source of shade . The representatives of the Sophora japonica dominate their environment and should therefore receive the appropriate attention and the ideal place. Difficulties and problems can always arise in the immediate vicinity of garden fences or house walls. Therefore, plant the tree in a solitary position so that it can demonstrate its full and lush beauty.
diseases and pests
All varieties of Sophora japonica are considered to be extremely resistant and are rarely or hardly ever attacked by pests and fungal pathogens. Many deficiencies in the tree are more likely to be due to a possible care error.
Honey fungus What counts as a culinary delicacy for many gourmets almost drives hobby gardeners to despair. The Armillaria mellea – the honey fungus – attacks the bark of deciduous and coniferous trees. The fungus grows parasitically, which means that the fungal strands penetrate the interior of the affected host plant and from there destroy its pathways. An infestation with honey fungus cannot be treated. There are neither effective home remedies nor strong chemical fungicides available to combat the fungus. In order to curb the spread, the entire tree must be felled and the soil must be completely replaced.
Honey fungus prefers older and already weakened trees. Prevent this and regularly check the condition of your decorative and useful trees in the garden. Healthy and strong plants can often defy the fungus by counteracting the destruction of the fungus by developing wound tissue.
Gray mold rot
Cold, damp weather and a lack of light favor infestation by Botrytis cinerea. This fungal pathogen causes gray mold rot, which often kills young plants. The first sign of this disease is white-grey discoloration on the leaves and young shoots. They spread quickly and then take on a brown color. Infected plants show growth damage, infected leaves wither and die. The gray mushroom lawn has a mealy, dusty substance.
Effective control measures are carried out on smaller plants by removing the affected parts of the plant and spraying a broth of nettles or field horsetails. Never dispose of the shoots and leaves in the compost, because the fungal pathogen can also hibernate on dead plant parts and spread from there in spring. For larger trees, you should use chemical agents and apply them according to the package instructions.
Only a few small varieties of the Japanese cord tree are available in specialist shops. The best known of these include:
- Sophora japonica ‘Regent’ – A cone-shaped crown and white flowers are the characteristics of this plant. The maximum growth height and width is about 16 meters. As a special feature, this cord tree flowers at a young age.
- Sophora japonica “Pendula” – This species is the “dwarf” among the cord trees. With a height of just 6 meters and a growth width of 3 meters, this plant is also suitable for smaller gardens. The characteristic feature of the “mourning cord tree” is its bizarrely shaped, hanging and intertwined branches. This variety flowers less frequently and less profusely than other Japonica varieties.
- Sophora japonica “Violacea” – With a growth height of about 12 meters, this cord tree joins the league of medium-sized cord tree species. The flower color of the “Japonica Violacea” is pink-white.
A Japanese cord tree is well suited as an impressive eye-catcher for a spacious garden. The lush growing tree is easy to cultivate and at the same time offers bees and other insects a rich source of food. The hardy and robust Sophora japonica defies even widespread pests and fungal pathogens, so the branches only have to be cut back to a limited extent.