A Detailed Guide to the Effects and Cultivation Methods of Rehmannia Root

Rehmannia is a kind of Chinese medicinal herb that often grows in wasteland, hillsides and other places. Because its root is yellow-white, it got this name. Rehmannia is cultivated in all parts of China. The dried rehmannia, raw rehmannia and prepared rehmannia that we are familiar with actually refer to its root. Rehmannia roots processed by different methods also differ in medicinal effects, so everyone must pay attention. So what are the effects of rehmannia root? How is it cultivated?

I. What are the effects of rehmannia root?

Fresh rehmannia root mainly has the effect of clearing heat and cooling blood. The slightly dried one is called raw rehmannia, and its medicinal effects are basically similar. Prepared rehmannia root mainly has effects such as tonifying qi, lowering blood pressure and treating irregular menstruation. But everyone should not casually buy and take it from a pharmacy on their own, because not everyone is suited to eating rehmannia root. For example, people with weak spleen and stomach, diarrhea and similar conditions are not suited to eating rehmannia, as this will worsen the symptoms. If someone has eaten foods such as radish or scallion white, it is also not recommended to take rehmannia.

Note that when decocting rehmannia in water, do not use copper or iron vessels; simply decoct and take it directly in a ceramic medicinal pot.

II. How is rehmannia root cultivated?

1. Choose a suitable planting site

For planting rehmannia root, the soil should generally be sandy soil with good drainage, good aeration, deep soil and fertility, as this is more conducive to the growth of rehmannia. Base fertilizer should be mixed into the soil, and generally well-rotted compost is a good choice.

2. Seed selection

Rehmannia is a medicinal herb propagated by rhizomes. Generally, one should choose rehmannia with few diseases, strong disease resistance, relatively high yield, good quality and good adaptability to the environment for seed use. Usually a small section from the middle is taken, then cut into a small segment, leaving two or three bud eyes, and then the cut surface is disinfected; after drying, it can be planted.

3. Daily management

(1) Thinning and replanting: When the rehmannia seedlings grow to about 10cm, thinning can begin. If rainy weather occurs, replanting should be done immediately to ensure the later harvest rate.

(2) Weeding: During the seedling stage of rehmannia root, weeds easily appear, but rehmannia is a shallow-rooted plant, so when pulling weeds, be sure to move gently, otherwise the rehmannia roots will be damaged.

(3) Watering: The early growth of rehmannia root requires a large amount of water, so the number of waterings should be relatively high, but waterlogging must not occur, otherwise root rot will appear. In the later stage, when the underground rhizomes are swelling, the number of waterings and the amount of water should be reduced. When the rainy season arrives, pay attention to draining accumulated water in time.

(4) Topdressing: Rehmannia is very fond of fertilizer. If fertilizer is insufficient, the roots will be small and growth will be slow. The base fertilizer applied early can only meet the growth needs of the seedling stage. In the later stage, during the root swelling period, topdressing should be done once or twice.

4. Pest and disease control

Common pests and diseases of rehmannia usually begin to appear in May, generally including fusarium wilt, leaf spot disease, red spider mites, cutworms and so on. Therefore, professional pesticides should be selected for targeted treatment, and pesticides must be used in accordance with national regulations.

In summary: the effects of rehmannia root differ according to whether it is raw or prepared, so everyone must pay attention when purchasing. If you are cultivating rehmannia, you should also pay attention to the several details mentioned above.