Key Cultivation Techniques and Planting Methods for Gleditsia sinensis Thorns

The Gleditsia sinensis thorn tree is a legume plant. It is a deciduous tree that can reach a height of 15-20 m, with a canopy spreading up to 15 m. Its thorns are slender and weak, reddish-brown, and often branched. It has even-pinnate compound leaves with 4-7 pairs of leaflets. The leaflets are ovate, ovate-lanceolate, or oblong-ovate in outline, 3-8 cm long and 1-3.5 cm wide, with a blunt apex that is sometimes notched, an obliquely rounded or wedge-shaped base, and finely serrated margins. The flowers are polygamous, borne in axillary and terminal racemes. All floral parts are covered with fine soft hairs. The calyx is campanulate with 4 ovate-lanceolate lobes; the corolla has 4 pale yellowish-white petals that are ovate or oblong-elliptic; there are 8 stamens, 4 long and 4 short; the ovary is linear and flattened. The pods are straight and flattened, glossy, dark purple, covered with a white bloom, 12 cm-30 cm long, containing numerous flattened, oblong-elliptic seeds about 10 mm long, reddish-brown and glossy. Most thorns are branched. The main thorn is cylindrical, 5 cm-15 cm long, about 8 mm-12 mm thick at the base, with a sharp tip. Branch thorns are typically 1.5-7 cm long and sometimes branch again into small prickles. The surface is brownish-purple with a reddish-brown tip, smooth or finely wrinkled, hard and difficult to break. The xylem is yellowish-white, and the center consists of light grayish-brown, loose pith. It is odorless and mild in taste.

It flowers every year in May, the fruit ripens in October, and the thorns reach full growth.

I. Seed TreatmentThe seeds of the "thorn-producing tree" have the thickest and hardest suberized seed coat among seeds. They are dark brown, flattened-elliptic, with an inconspicuous latent embryo located at the slightly concave point at the small end of the ellipse. Because the hard suberized layer makes it very difficult for water to enter, special treatment is required for germination.

1. Boiling water soaking method: Place the seeds in a container, pour 100°C boiling water from a kettle over the seeds, stirring with a wooden stick while pouring. Stop adding water once the water level covers the seeds, and continue stirring until the water temperature reaches 40°C. Cover the container tightly and soak for 12-20 hours. Separate the swollen seeds floating on the surface and place them in another container, cover with pure cotton cloth to retain moisture, and wait for sowing or sow in batches. For seeds that have not swollen, repeat the above boiling water method. Seeds that have not swollen after several soakings are non-viable seeds that cannot germinate.

2. Sandpaper abrasion method: The sandpaper abrasion method involves grinding the seed coat at the large end of the seed on No. 0 fine sandpaper (do not grind the embryo at the small end). As long as the abraded seed coat allows water to enter easily, the seed will swell. Soak the abraded seeds in room-temperature water for 12 hours and they are ready for sowing. The sand abrasion method has a higher germination rate than the water soaking method, and this method is generally used.

II. PlantingFor the planting season, the north is suitable for sowing from April to June, while the Central Plains and areas to the south are suitable for sowing from March to July. The ideal time is when the natural temperature in different regions stabilizes at 13°C. Planting can be done by two methods: raising seedlings first and then transplanting, or direct sowing.

1. Seedling raising method: Apply sufficient decomposed farmyard manure in the seedling bed (unfermented raw manure is prohibited) at about 4 cubic meters per mu as base fertilizer (do not use chemical fertilizers). Water the seedling bed thoroughly. After the water has completely soaked into the ground, evenly scatter the seeds on the seedling bed and cover with 5 cm of loose fine soil. Ridging for seedling raising can also be used: open a 5 cm deep furrow on the ridge, irrigate thoroughly, and dibble the swollen seeds at 5 cm spacing in the furrow, covering with no more than 4 cm of soil.

2. Direct sowing method: Direct sowing should be carried out when soil moisture is good, the ground is moist, and irrigation conditions are available. Open a 5 cm deep furrow along the defense line. If the soil moisture is insufficient, irrigate before sowing. The sowing method can follow the dibbling method described above for ridge seedling raising. The spacing should not exceed 6 cm. If there are underground pests, mix an appropriate amount of pesticide with the swollen seeds to ensure the emergence rate.

III. TransplantingWhen seedlings have grown to 25-30 cm, they can be transplanted along the defense line. It is best to transplant with a soil ball. First open a planting furrow 15 cm deep along the defense line. The planting depth should be at the original soil mark of the seedling from the seedbed. Space plants 20 cm apart. After planting, irrigate thoroughly. When cracks appear in the ground on both sides of the seedlings, carry out one intertillage when moisture is suitable to preserve soil moisture. After the seedlings are fully established, apply an appropriate amount of urea when watering or during rain to promote seedling growth. Transplanting of one-year-old seedlings should be done after leaf fall in autumn or before bud break in spring.

IV. Post-Planting Management At present, no pests or diseases have been found on the "thorn-producing tree" in our country. If pests or diseases occur in different regions, an appropriate amount of pesticide can be sprayed according to the type of pest. Under good water and fertilizer conditions, the "thorn-producing tree" grows very well in northern regions.