How to Grow a Radermachera sinica (China Doll) and Points to Note: Remember These Eight Tips for Lush Growth

Many people place a pot of Radermachera sinica (China Doll) at home, as it symbolizes good fortune and beauty. The China Doll is an excellent large foliage houseplant, generally grown indoors, for example in large banquet halls and office spaces where it is displayed more often. So what are the growing methods and points to note for Radermachera sinica? How often should it be watered?

I. Basic Information on Radermachera sinica

1. Other names for Radermachera sinica

Radermachera sinica is also called caidoushu, shan caidou, kulinjiu (Taiwan, China), jiangdou shu (Funing, Yunnan), lajiao shu (Hekou, Yunnan), jiegu liangsan, senmu liangsan, chaoyang hua, niuwei mu (Guangxi Practical Chinese Herbal Medicine), doujiao mu, niuwei dou, shezai dou, jidou mu, da chaoyang (Guangxi Chinese Veterinary Medicinal Plants), diesimao shu (Hainan), and in Taiwan, China it is also commonly known as wangwang shu or jincai shu.

2. Origin of Radermachera sinica

Radermachera sinica is a plant of the genus Radermachera in the family Bignoniaceae, distributed in Bhutan, Taiwan, China, Guangdong, Yunnan, Guizhou, Guangxi and other places, growing at altitudes of 340 m to 750 m, generally in valleys and open forests on flat land. It is also a common garden plant, and because of its extremely shade-tolerant nature, it is one of the few woody plants that can be placed indoors.

3. Morphological characteristics of Radermachera sinica

Radermachera sinica is a medium-sized deciduous tree, up to 15 m tall, with light gray bark. The leaf rachis is about 30 cm long, the leaves are alternate, the middle leaflets are opposite, ovate or ovate-lanceolate, 4 cm to 7 cm long. The inflorescence is upright, terminal, 25 cm to 35 cm long, 30 cm in diameter, the corolla is campanulate-funnelform, white or pale yellow, 6 cm to 8 cm long. The capsule is leathery, cylindrical and elongated like a green bean, slightly curved with many grooves.

II. Growing Methods and Points to Note for Radermachera sinica

If you want Radermachera sinica to grow luxuriantly, you need to understand its ecological habits, and during cultivation you should pay attention to factors such as soil, water, light, fertilizer, temperature and humidity. Therefore, we should pay attention to the following eight growing methods and points to note:

1. Soil requirements for growth

Radermachera sinica is suitable for loose, fertile culture soil that drains and breathes well and is rich in organic matter. Generally, sandy loam soil can be selected, and garden soil, leaf mold, decomposed organic fertilizer and river sand can be mixed in a ratio of 5:3:1:1.

2. Temperature and humidity requirements for growth

Radermachera sinica prefers a warm and humid environment. The suitable growing temperature is between 15 and 25°C. During high summer temperatures, the temperature should also be kept below 27°C as much as possible, with appropriate shading by building a frame. In winter, the temperature should be maintained above 8°C, and must not fall below 5°C. Humidity should be kept between 70 and 80%. When the temperature is too high and the air is too dry, water should often be sprayed on the leaves of the Radermachera sinica.

3. Light requirements for growth

Radermachera sinica is a plant that likes sun and also tolerates shade, and can grow in full sun or semi-shade environments. In summer, care should be taken to build a frame for shading, and it must not be exposed to blazing sun. When potted Radermachera sinica is placed indoors, it is best placed by a window or on a balcony with ample light, and not kept for a long time in dark places where neither direct light nor scattered light can reach, as this easily causes leaf drop. In winter, potted Radermachera sinica can be placed in a higher position in front of a window or balcony so that it receives more light.

4. Water requirements for growth

During the high-temperature summer season, Radermachera sinica must have sufficient water, but waterlogging must not occur. In spring and autumn, the amount of watering should be controlled, as long as the potting soil stays moist. In winter, watering should be reduced, otherwise waterlogging and root rot easily occur.

5. Fertilizer requirements for growth

For potted Radermachera sinica that has been purchased for more than three months, fertilizer should be appropriately applied to the roots. Fertilizing can begin each spring when new branches and buds emerge, once a month, generally using a compound fertilizer containing nitrogen, phosphorus and potassium or an organic fertilizer (you can also make your own using fermented rice-washing water or various bones ground into powder). Compound fertilizer is applied by watering, dissolved in water and then poured on, at a concentration of 0.5% to 1%; organic fertilizer is applied by burying. Note that no fertilizing is needed in summer and winter.

6. Pruning essentials

Radermachera sinica is a large foliage houseplant, so it should usually be pruned appropriately into the shape you want. Some old branches, diseased branches and lower branches should be dealt with together and cut off. During pruning, it can be shaped at will, such as umbrella-shaped, tower-shaped, round, etc.

7. Pest and disease control

(1) In environments with too high temperature, high humidity and poor ventilation, the leaves of Radermachera sinica are prone to leaf spot disease. Strengthen ventilation and light transmission, and spray with a 600-fold dilution of 50% carbendazim wettable powder once every 15 days.

(2) The main pest of Radermachera sinica is scale insects. If there are few, simply wipe them off with a rag; if there are many, they can be eliminated by spraying with a 1500-fold dilution of 25% buprofezin wettable powder. Secondly, pay attention to strengthening ventilation and light transmission, and controlling environmental humidity.

In fact, Radermachera sinica has quite strong disease resistance. As long as it is ventilated and aired frequently, it generally will not suffer from pests.

8. Repotting

Radermachera sinica should be repotted once every 1-2 years, moving to a slightly larger pot each year, while adding base fertilizer and replacing with new nutrient soil so that it grows vigorously.

Whether Radermachera sinica grows well still depends on your usual care. In winter, pay attention to keeping it warm, prune regularly, replace the potting soil every year, water appropriately, and never pour tea water into the pot or throw in garbage.

III. How Often Should Radermachera sinica Be Watered?

As mentioned above, attention should be paid to the water requirements of Radermachera sinica during its growth periods. The amount of watering differs by season, and the amount should also be determined according to the actual condition of the plant. Specifically, note the following points:

1. During the high-temperature summer season, Radermachera sinica must have sufficient water, so water once every 3-4 days, depending on the condition of the plant;

2. In spring and autumn, control the amount of watering, once a week;

3. In winter, when the weather is cold and Radermachera sinica is almost in a dormant period, water only after observing that the potting soil has dried out completely, and when watering, make sure to water thoroughly.

Conclusion: The above is an introduction to growing Radermachera sinica. We hope it is helpful to everyone. As a foliage potted plant, Radermachera sinica can usually be placed in the living room, study, balcony and other places, and can have a calming effect and help purify the air.