Aster Cultivation Methods and Key Technical Points

        Aster is also known as "little braid mountain aster" and "donkey ear cai". It is a plant of the genus Aster in the family Asteraceae and is a commonly used traditional Chinese medicine. The roots and rhizomes are used medicinally, and it has effects such as dispersing cold and moistening the lungs, and directing qi downward and resolving phlegm. It is mainly produced in Anguo City, Hebei Province, and Anhui, and is cultivated in various places. Aster is a perennial herb, 40-150 cm tall, with a short rhizome, bearing many clustered fine roots, and the outer bark is grayish brown. The stem is erect; the upper part is much branched. The basal leaves are large, clustered, and spoon-shaped. They fall off at flowering time, and the stem leaves are relatively small, lanceolate. The capitula are arranged in a compound corymb, with short hairs on the pedicels, the margin has ligulate flowers that are light purple, and the center has bisexual tubular flowers that are yellow. The achene is oblong-obovate, flat, and the pappus is grayish white or light brown. The flowering period is August-September, and the fruiting period is September-October.          I. Growth Habits          It prefers a mild and humid climate and is afraid of drought, especially during June-July, the period of fastest leaf growth; if there is a lack of water, growth is hindered and yield is affected. It has strong cold resistance. In the north, the roots can overwinter in the soil. It has no strict requirements for soil, and can be planted in all soils except saline-alkali land and excessively sandy land. However, fertile sandy loam gives high yields.          II. Propagation          Aster is propagated by rhizomes. The suitable sowing period is early April, and the suitable density is 17,000 holes/mu. Each mu requires 15-20 kg of rhizomes.          1. Land Selection and Land Preparation          Choose flat terrain, deep soil layer, loose and fertile loam or sandy loam with convenient drainage and irrigation, and plow more than 30 cm deep before winter so that the soil is fully weathered. In combination with land preparation, apply 10,000-15,000 kg of decomposed farmyard manure per mu, plus 50 kg of cake fertilizer, and plow it into the soil as base fertilizer. Before planting, shallow plow again, level and harrow finely to make high beds 1-1.2 m wide, and open relatively deep drainage ditches around them.          2. Aster Planting Material Treatment Techniques          Cut off the lower young and tender part and the upper reed head part, take the middle section, and cut it into 5-7 cm small sections; each section must have 2-3 dormant buds. Aster planting is divided into spring planting and autumn planting. Spring planting is done after the soil thaws in spring, no later than the Spring Equinox, and autumn planting is around Frost's Descent; for spring planting, cut and plant immediately. Autumn planting for seed preservation requires winter storage; the specific method is: dry the planting material slightly, place it in a cellar for storage, spread sand on the cellar bottom, then place one layer of planting material and one layer of sand, cover the top with sand, and keep the cellar temperature just above freezing to prevent heating and rot, storing until planting the following spring.          3. Planting Method          Open shallow furrows 6 cm deep at a row spacing of 21-24 cm, with a plant spacing of 12-15 cm, place 2-3 small sections per hole, lay the planting material flat in the furrow, then cover with soil and push flat and firm with a hoe. Each mu uses 40-45 kg of planting material.          III. Field Management          1. Watering and Drainage          For spring planting, if drought occurs, water 1-2 times before emergence; if the soil moisture is suitable, seedlings can emerge in 10-15 days. For autumn planting, water once before freezing, and cover with a layer of soil and miscellaneous fertilizer or horse manure to prevent cold and preserve moisture for safe overwintering. Aster likes moisture and is afraid of drought. During the peak growth period in June-July, it needs more water, and when there is drought, it should be watered in time to keep the soil surface moist. During high temperature and drought in autumn, water 2-3 times. In the rainy season, pay attention to dredging ditches for drainage; the field must not accumulate water, otherwise root rot is likely to occur.          2. Cultivation and Weeding          Carry out 3-4 times each year. The first time is after full emergence, and shallow loosening of the soil is appropriate to avoid damaging the roots; the second time is when the seedlings are 7-9 cm tall; the third time is before the plants close the rows; after the rows close, pull out weeds by hand if any. Topdressing is carried out 2-3 times each year. The first time is after full emergence, in combination with cultivation, applying 1,500 kg of human and livestock manure water per mu; the second time is when the seedlings are 10 cm tall, applying another 1,500-2,000 kg of human manure water; the third time is before the rows close, applying 500-1,000 kg of compost per mu plus 50 kg of cake fertilizer, mixed and composted, then applied in furrows beside the plants and covered with soil after application. Around the Beginning of Autumn, apply 10-15 kg of urea per mu as topdressing, irrigating it into the beds with water.          3. Removal of Flower Stalks          Aster should use purplish-red rhizomes with axillary buds as propagation material; these do not bolt and flower. If reed heads are used for propagation, they will bolt, flower, and set seed, consuming a large amount of nutrients. Except for seed preservation, production uses the method of cutting off flower stalks to promote rhizome growth and development. Therefore, when bolting is found in August-September, cut off all flower stalks on a sunny day.