How to Grow Rehmannia: Rehmannia Planting Techniques and Precautions

Rehmannia is a traditional Chinese medicine, and ordinary people cannot buy it at the vegetable market. So some people feel it is inconvenient to buy, and wonder whether they can grow it at home. Of course they can, but do you know how to grow Rehmannia? To answer everyone's questions, the editor has specially gathered related information on Rehmannia and compiled it into the following material for everyone to refer to and read. Let's take a look.

How to Grow Rehmannia

1. Site Selection and Planting of Rehmannia

Choose flat terrain that is convenient for irrigation and drainage, with deep soil layers, loose soil texture, rich organic matter, and good water- and fertilizer-retention sandy loam soil. The rotation period is ten years.

2. Variety Selection of Rehmannia

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3. Land Preparation

In combination with soil preparation, apply 5 parts fully decomposed coarse manure and mixed fertilizer per mu to control underground pests, nematodes, Fusarium wilt virus, stem base rot, and other pests. After sowing, along the sowing rows, carry out soil disinfection treatment with a mixed solution of agricultural Kang 120 + Guanglingling to prevent diseases such as Fusarium wilt.

4. Sowing of Rehmannia

1. Soil disinfection of the land: cover with plastic film in mid-April to ensure complete seedling emergence.

2. Suitable planting time for Rehmannia: use plastic film mulching in mid-April to ensure full emergence of seedlings in one sowing.

3. Seed soaking of Rehmannia seedlings: soak in 25% Shibaike 1500× or Junkeduke 250× or OS-Shiteling 250 times solution for 30 minutes, then dry and wait for sowing.

4. Weeding method for Rehmannia: soil sealing chemical weeding: from the end of March to the beginning of April, treat seedlings before sowing with 200 ml Shitianbu and 45-50 kg water for soil sealing treatment.

Rehmannia Planting Techniques and Precautions

1. Rehmannia Planting Techniques

1. Environmental Requirements

Rehmannia is a highly light-demanding plant, and the planting site should not be close to forest edges or intercropped with tall crops. It needs sufficient sunlight throughout the growing period, prefers dry conditions, fears waterlogging, and can tolerate cold. Otherwise, diseases will be severe. Rehmannia has “three fears”, namely fear of drought, fear of waterlogging, and fear of pests and diseases. When the soil temperature is 11-13°C, emergence takes 30-45 days; 25-28°C is most suitable for germination. Within this temperature range, if soil moisture is suitable, it will germinate one week after planting and emerge from the soil in 15-20 days. The rhizome cannot germinate below 8°C.

2. Soil Requirements

The growth of Rehmannia has unique requirements for soil and fertilizer. It is best to choose sandy loam soil with deep soil layers, loose and fertile texture, and good drainage. The pH requirement is neutral or slightly alkaline, and plots with higher organic matter content are best. Plots with heavy clay soil, waterlogged low-lying land, or shade cannot be used for cultivation. In particular, note that Rehmannia should not be continuously cropped, which is also a key measure to pay attention to when selecting land. When cultivating Rehmannia, the previous crop should preferably be a grass-family crop, and land that has previously grown cotton, sesame, beans, melons, etc. should not be chosen, in order to control underground pests. In combination with land preparation, apply 2000 kg decomposed compost, 25 kg superphosphate, and 50 kg compound fertilizer per mu as base fertilizer, and deep plow more than 25 cm. Then level and harrow finely to make beds, generally 1.3-2 m wide. At the same time, 1.5-2 kg of 50% thiram + 0.8-1 kg of 1.8% abamectin can be mixed with 30-40 kg fine sandy soil per mu to make poisonous soil and spread it before plowing (harrowing) to control nematodes, Fusarium wilt, stem rot, and other pests.

3. Water Requirements

In the early stage of Rehmannia growth, the soil moisture requirement is low, about 10-20%. In the middle and late growth stages, which is also the tuber expansion period, the soil should be kept moist, but not waterlogged. Because its root system is small and its water absorption capacity is poor, it easily wilts with slight drought; if there is too much soil moisture, the fleshy rhizome easily rots, so appropriate irrigation is needed.

4. Seedling Raising and Planting

(1) Seedling raising. Generally speaking, cultivated Rehmannia used as propagation material has roots, and the production is called “planting”. For Rehmannia “seedlings”, generally the “reverse-planted” “seedlings” cultivated in July-August of the previous year are selected, because when “reverse-planted” “seedlings” are used as seed material, Rehmannia has high yield, good quality, and can prevent variety degeneration. Specific method: in July-August, in a field of fine-variety Rehmannia planted in spring of that year, select robust rhizomes free of pests and diseases, dig them up and break them into short sections of 4-5 cm, air-dry them slightly, and plant them in a field fully supplied with sufficient base fertilizer at a row spacing of 15-20 cm and a plant spacing of about 10 cm. Weed appropriately, topdress, pay attention to drainage after rain, and in the second year in spring, they are dug up for planting.

(2) Planting. Each acre requires 40 to 60 kg of “planting material”. When the daily average temperature is 18 to 21°C, each mu requires 40-60 kg of “seedlings”. When planting, dig holes 3 cm deep on the bed at a row spacing of 15-20 cm and a plant spacing of 15-18 cm. Place 1-2 sections of seed rhizome in each hole, cover with 3-4 cm of soil, compact the surface soil, water, and then cover with film (film covering can increase ground temperature and also has a moisture-retention effect). This is usually the best way to plant Rehmannia.

2. Precautions for Rehmannia Planting

Ensure the seedlings are full 0.71776. When digging, open a 35 cm deep trench at the end of the bed. For processed organic Rehmannia, use a special roasting oven to process it into prepared Rehmannia, which then becomes a commodity. The leaves, flowers, and rhizomes of organic Rehmannia can all be used as medicine. For Rehmannia leaves, in the late growth stage of Rehmannia, select robust, disease-free plants, appropriately pick some leaves, and dry them in a cool place. Organic Rehmannia leaves mainly treat malignant sores and tinea of the hands and feet, while the flowers have the effects of relieving thirst and treating kidney deficiency and lower back pain. Therefore, harvesting should be carried out at the appropriate time. For the harvest of organic Rehmannia flowers, during the flowering period, choose a sunny day, and in combination with bud thinning, collect the flowers and buds, carefully remove the roots, and dry them in a cool place.

Rehmannia Harvesting Methods

Use a shovel or sickle to cut the stems and leaves at the ground. Be careful not to cut too deep, so as not to damage the roots. After the aboveground part is cut off, use a rake to pull the cut stems and leaves to one side, exposing the soil surface to facilitate harvesting of the rhizomes. Use a shovel or pickaxe to dig at one end of the bed, with a trench depth of about 35 cm. The digging depth should be such that the rhizomes are not damaged. Organic Rehmannia breaks easily, so be very careful when digging. The picking process should also minimize damage to the rhizomes. Each mu can harvest 1000-1500 kg of fresh organic Rehmannia, and the yield per mu can reach 2000-2500 kg.

After reading the above information, I wonder whether it has discouraged some people from the idea of growing it. In fact, the requirements for growing it are very high. Without professional knowledge and technical equipment, it is very difficult to grow successfully, so everyone should just honestly go to the store to buy it. It will not be especially expensive.