How Much Is a Jin of Rehmannia Seeds? A Detailed Guide to Sowing Time and Planting Methods

Rehmannia, a perennial herb of the genus Rehmannia in the family Scrophulariaceae, with fresh rehmannia used as a heat-clearing and blood-cooling medicine, while prepared rehmannia is a tonic medicine. So, how much is a jin of rehmannia seeds on the market? When should they be sown? What are the planting methods?

1. How much is a jin of rehmannia seeds on the market?

The price of rehmannia seeds is about 60-100 yuan per jin, but it varies depending on seed quality, place of origin, variety and so on. Rehmannia varieties are mixed, and long-term asexual reproduction has led to degeneration, with great differences in yield; propagation by seed for rejuvenation is one of the means to overcome the degeneration of rehmannia.

2. When should rehmannia be sown?

It is best to plant rehmannia in spring. Generally, the best time is when the average daily temperature is 18-21°C. For example, in Beijing it is in early to mid-April, in Chongqing from late February to late March, and for early-spring rehmannia in Henan it is in early to mid-April; late rehmannia (or wheat-stubble rehmannia) is from early May to early June. When planting, open furrows on the ridges or beds, with a furrow spacing of 33 cm, place one section of planting material every 15-20 cm, cover with 3-4 cm of soil, firm the surface soil and then water. Plant 2 rows per ridge and 3-4 rows per bed. After the seedlings emerge completely, fill in gaps on cloudy and rainy days; about 1 month after planting, thin the seedlings, keeping 1 healthy seedling per hole. Before the rows close, shallow hoe 2-3 times and remove the excess seedlings that keep appearing.

3. What are the planting methods for rehmannia?

1. Site selection and land preparation: For rehmannia, choose sandy loam with deep soil, fertility and good drainage. At the same time, apply 2000-3000 kg of decomposed compost and 25 kg of superphosphate per mu as base fertilizer. Then level and harrow the soil fine to make beds. Pay special attention that rehmannia should not be planted continuously on the same land.

2. Thinning and filling gaps: When the rehmannia seedlings are 10-12 cm tall, begin thinning, keeping 1 strong seedling per hole. If there are missing plants, replant promptly on cloudy days, and when replanting, lift the seedlings with soil, as this gives a higher survival rate.

3. Cultivation and weeding: The rhizomes of rehmannia are relatively shallow in the soil, so cultivation should be shallow to avoid damaging the roots. Weeds around the seedlings should be pulled out by hand, and once the plants close their rows, stop cultivation.

4. Reasonable topdressing: Rehmannia likes fertilizer. In addition to applying enough base fertilizer, after thinning, apply 100 kg of superphosphate and 30 kg of decomposed cake fertilizer per mu to promote rhizome development and swelling. When the rows close, broadcast 1 application of burnt soil ash between the rows to promote robust plant growth.

5. Timely irrigation: Rehmannia needs a lot of water in the early stage, so water frequently. In the later stage, which is the period of underground rhizome swelling, water should be saved. In the rainy season, drainage should be done promptly to prevent root rot.

6. Remove creeping surface roots: Besides the main root, rehmannia can also grow slender underground stems along the soil surface, called creeping surface roots. These creeping surface roots consume a lot of nutrients and should be removed promptly during field management.

7. Disease and pest prevention: The main diseases of rehmannia are leaf spot, ring spot and wilt, generally beginning in early May and becoming severe in June-July, so timely control should be noted. Pests include red spiders, cutworms, white grubs and so on, controlled by conventional methods.

8. Harvesting and processing: When rehmannia is planted in spring, it should be dug promptly around November of that year when the aboveground stems and leaves turn yellow and wither. When digging, open a 35 cm deep furrow at one end of the bed, carefully take out the rhizomes in sequence, and then use a special roasting oven to process them into prepared rehmannia, which is then the commercial product.