How to Grow Pseudostellaria heterophylla? Detailed Guide to Cultivating This Chinese Medicinal Herb

Pseudostellaria heterophylla, also known as tongshen or hai'ershen, is a plant in the Caryophyllaceae family. Its roots are used medicinally and have the functions of tonifying qi and strengthening the spleen, promoting fluid production and moistening the lungs. It is used to treat fatigue due to spleen deficiency, poor appetite, spontaneous sweating and thirst, and dry cough due to lung dryness. It is mainly produced in Fujian, Anhui, Jiangsu, Shandong and other places. In recent years, it has also been cultivated in Zhejiang, Hunan, Guizhou and other provinces.

I. Plant Characteristics

Perennial herb, 7-20 cm tall, with long fusiform tuberous roots. Stems slender and weak, purple in the lower part, nearly square, the upper part nearly round and green. Leaves opposite; lower leaves spatulate or oblanceolate, upper leaves ovate-lanceolate to oblong-ovate; leaves at the stem tip often gathered in groups of 4, arranged in a cross shape. Flowers axillary, with 4 white sepals. Capsule nearly spherical, splitting open when mature. Seeds flat and round.

II. Growth Habits

It prefers a mild, moist and cool climate, and is intolerant of high temperatures and strong direct sunlight. It is afraid of drought and waterlogging, and is relatively cold-tolerant. It can still germinate and take root at temperatures below 15°C, but growth stops when the temperature exceeds 30°C. It is suitable for growing in loose, humus-rich sandy soil. Seedlings emerge in February-March, and then buds and flowers appear. From April to May the plants grow vigorously, and the underground stems produce roots, elongate and swell node by node. The fruiting period is May-June, and the seeds mature in June. After late June, the aboveground stems and leaves wither, a large number of leaves fall off, and at the time of "Major Heat" the plants die, the seed roots rot, and the new roots spread apart from each other in the soil, entering the summer dormancy period.

III. Key Cultivation Points

1. Choose the right site and prepare the soil carefully. Dry land on a slightly sloping north-facing hillside should be selected for planting, and virgin soil is especially best. To reduce sources of disease and lessen disease damage, a rotation should be carried out once every 2-3 years. Avoid previous crops in the Solanaceae such as tobacco, and vegetables; plots that previously grew gramineous crops are still acceptable. Deeply plow the planting site to 20 cm, make beds 0.8-1.4 m wide and 25 cm high, with the bed surface shaped like a turtle's back, and furrows 30 cm wide. Prepare the soil carefully so that the soil layer is loose. Fifteen days before planting, use 0.5 kg of 50% phoxim emulsifiable concentrate diluted to an 800-fold solution to spray the bed surface, then turn the topsoil into the soil layer to prevent underground pests.

2. Strictly select seed roots and plant at the right time. Choose plump, robust seed roots with intact buds, free of damage and disease, or use the seed-sowing propagation method to produce seed roots free of disease sources for production use, so as to cultivate disease-free strong seedlings and lay the foundation for a high yield. Plant around the time of Frost's Descent, using 20 kg of seed per mu. Before planting, soak the seeds in a 500-fold solution of 50% carbendazim for 30 minutes, drain, then rinse with clean water to remove residual liquid, air-dry, and wait to plant.

3. Apply sufficient base fertilizer and plant at a reasonable density. Pseudostellaria heterophylla plants are short, and the tuberous root is the economic target. To avoid damaging the roots or causing rot from contact between fertilizer and seed roots, intertillage and topdressing should not be done later on. Applying sufficient base fertilizer and maintaining a suitable planting density are key measures for high yield, with heavy application of base fertilizer as the main approach. Open planting furrows 10 cm deep across the bed surface, with furrow spacing of 13-15 cm. Per mu, use 1200 kg of plant ash, 40 kg of superphosphate, 10 kg of compound fertilizer, and 200 kg of human excrement and urine, compost them, then spread the mixture on the bottom of the furrows and cover with a thin layer of soil. Place the seed roots at a plant spacing of 4-6 cm, with the buds 6 cm from the soil surface, with the heads and tails of the seed roots touching, then cover with fine soil to cover the seeds.

4. Protect soil moisture, maintain moisture, and apply balanced fertilizer as appropriate. Twenty-five days after seedling emergence, weeds should be pulled and the topsoil lightly loosened. After the seedling stage, the soil should not be loosened. Pull weeds when the rows close, and stop soil moisture activities after the rows close to promote the growth of the roots. During the growth stage, it is advisable to keep the soil moist and the bed surface free of standing water. During the tuberous root swelling stage, water frequently to promote the growth and development of the tuberous roots. For plots with strong seedlings, fertile soil and sufficient base fertilizer, topdressing should not be applied, to avoid excessive vegetative growth of branches and leaves. If the growth of the aboveground and underground parts is unbalanced, fibrous roots will increase and yield will decrease. However, for plots with insufficient base fertilizer, poor soil fertility, few branches at the seedling stage and weak seedling frames, around Qingming apply 30-40 kg per mu of decomposed cake fertilizer mixed with soil into the bed, or use foliar topdressing such as "Yunda 120" and "brassinolide" to improve the light energy efficiency of the population, delay the withering of stems and leaves, prevent premature aging, and promote the proliferation and swelling of tuberous roots. Scientific application of balanced fertilizer is crucial to increasing yield.

5. Harvest at the right time and retain seed roots. Around the time of Summer Solstice in the year following planting of Pseudostellaria heterophylla, when more than 50% of the aboveground stems and leaves have withered, harvesting should begin, as the finished product rate of the roots is highest at this time. Harvesting should be done on sunny days, and both large and small roots should be harvested completely. Select roots that are disease-free, have stable characteristics, plump buds and are robust to retain as seed roots, and place them in a cool place, layering them repeatedly in 4-5 layers of sand (10 cm thick) and seed roots. During storage, keep the sand layer moist, turn and inspect the pile every 20 days, pick out moldy and rotten seed roots, and before planting select the best from the best to ensure the quality of the seed roots and lay the foundation for a high yield the following year.

IV. Processing Techniques

1. Processing of sun-dried roots. Wash the harvested roots, sun-dry until half dry, then pile them up to let them absorb moisture again, and then spread them out to sun-dry. During the drying process, place the roots on a wooden board and rub off the fibrous roots by hand until the roots are smooth and free of hairs.

2. Processing of blanched roots. Spread the harvested roots to air-dry for 1-2 days, and after the roots lose water, wash them and blanch them in boiling water at 100°C for 1-3 minutes, until a fingernail can be pressed smoothly into the root body. Then sun-dry them, put them into a bamboo basket, and shake and strike lightly to remove the fibrous roots, thus producing blanched roots. Product characteristics: smooth surface, pale yellowish-white color, soft texture.

V. Issues That Should Be Taken Seriously

In recent years, with the development of the Pseudostellaria heterophylla industry, due to the lack of standardized scientific cultivation technical guidance, growers have tended to act arbitrarily and blindly in production, leading to rampant disease, with viral mosaic disease, leaf spot disease and root rot disease occurring severely, degeneration of seed quality, reduced yield and poorer quality, ultimately affecting the effect of increasing production and income per unit area. Growers must attach great importance to this. In production, integrated pest and disease control and purification and rejuvenation of seed sources should be strengthened, and markets should be further developed to ensure the steady development of the industry.