Purple locust tree is a tree up to 25 meters high; the bark is grey-brown with longitudinal cracks. The branches of the current year are green and hairless. The pinnate compound leaves are up to 25 cm long; the leaf rachis is sparsely pubescent at first, and soon becomes clean; the base of the petiole is enlarged and wraps the bud; the shape of the stipules is variable, sometimes ovate, leaf-shaped, sometimes linear or subulate, early fall.

Leaves 4-7 pairs, opposite or nearly alternate, papery, ovate-lanceolate or ovate-oblong, 2.5-6 cm long, 1.5-3 cm wide, apex acuminate. With a small pointed head, the base is broadly wedge-shaped or nearly round, slightly skewed, the underside is grayish white, sparsely pubescent at first, then becomes hairless; there are 2 small stipules, diamond-shaped.

The pods are bead-shaped, 2.5-5 cm or slightly longer, and about 10 mm in diameter. The constriction between seeds is not obvious, and the seeds are closely arranged. They have fleshy pericarp, do not crack when mature, and have 1- 6 seeds; seeds are ovoid, light yellow-green, dark brown when dried. The flowering period is from June to July and the fruiting period is from August to October.

Sophora japonica is a characteristic tree species commonly used in courtyards. It has dense branches and leaves and a canopy of green leaves. It is suitable as a shade tree in the courtyard. It is often used as a street tree in northern China. It is also very suitable for planting in parks, around buildings, in residential areas and on lawns. Sophora japonica should be planted opposite or in rows in front of the door, or planted alone beside the rocks on the pavilion. It can also be used for greening in industrial and mining areas.

The flowers can be seen in summer and autumn and are excellent nectar plants. The flower buds can be used as dyes, the pulp can be used as medicine, and the seeds can be used as feed. It is also a windproof and sand-fixing tree species that can be used as both timber and economic forest. It is a good shade tree and street tree species in urban and rural areas. It has strong resistance to toxic gases such as sulfur dioxide and chlorine. Sophora japonica can also be selected as a tree species in mixed forests.

Extended information

Sophora japonica is used for greening seedlings. It usually takes 3 to 4 years to emerge from the nursery. Because the top branches of the seedlings have dense buds and short spacing, the trunks are easy to bend. Annual seedlings are transplanted at a spacing of 40-50cm between plants and 70-80cm between rows. After planting, the main trunk can be cut dry at a distance of 3-5cm from the ground.

Because the Sophora japonica tree has germination ability, a large number of sprouts are likely to sprout after cutting. When the budding branches grow to about 20cm, select one strong upright branch as the main trunk and remove all the remaining branches. . In the future, always pay attention to removing tillers and sides, and temporarily retaining the weak side branches on the upper, middle and lower parts of the main trunk, which is beneficial to prevent the main trunk from bending. In this way, the seedling height can reach more than 3m in the next year.

The frequency of watering Chinese Sophora japonica seedlings should be determined based on factors such as climate conditions, soil texture, etc. Under normal circumstances, water 2 to 3 times after emergence to before the rainy season, water once to seal the nursery before it freezes, and drain water in time when waterlogging occurs.

Before sowing, apply about 3,000kg of base fertilizer (mainly organic fertilizer or circle fertilizer) to the seedling land. In early June, combined with watering, topdressing of quick-acting nitrogen fertilizer (such as urea) 8~10kg, 7~ Topdress urea in August (it is best to add an appropriate amount of compound fertilizer 12 to 3 times, and the amount of fertilizer applied each time is about 30kg. No more watering and fertilizing after September to promote lignification of seedlings.

Baidu Encyclopedia - Sophora japonica (Pelumaceae)