What is the best planting date of Angelica dahurica (technical management of Angelica dahurica planting)

Angelica dahurica is propagated by seeds, which can be sown in spring or autumn, usually in autumn, from late August to early September; Spring sowing was carried out in the middle and late April, and the yield and quality were poor. Angelica dahurica is not suitable for seedling raising and transplanting, and it adopts direct seeding in the field, with many transplanted lateral roots, poor growth and poor quality of main roots. Choose sandy soil or sandy loam with flat terrain, deep plough layer, loose and fertile soil and good drainage. After the previous crop is harvested, apply 2,000-3,000 kilograms of farm manure and 50 kilograms of calcium superphosphate every 667 meters, turn it over 30 centimeters deep, rake it flat, and make a border with a width of 100-200 centimeters and a height of 16-20 centimeters. On the whole border, dig shallow border with a row spacing of 30cm, and the depth of the border is 1.5cm, evenly spread seeds in the border, cover the soil, compact, and germinate after sowing 15~20 days. The sowing amount is 667 m21.5 kg.