Chinese medicine refers to the dried bark, root bark, and branch bark of Magnolia officinalis as thick magnolia. Thick magnolia has a good therapeutic effect on diseases such as food stagnation, abdominal distension and constipation, and dampness obstructing the middle jiao. However, due to the medicinal use of thick magnolia mainly being its bark and root bark, excessive stripping and deforestation have caused a sharp reduction in thick magnolia resources. Wild plants are now very rare, and most are cultivated artificially. They are mainly distributed in Shaanxi, Gansu, Henan, Hubei, Hunan, Sichuan, Guizhou and other provinces in China. So, what kind of ecological environment is suitable for planting thick magnolia? Let's take a closer look at the growth environment of thick magnolia.
1. Ecological Environment of Thick Magnolia
Thick magnolia grows in sunny slopes with fertile and deep soil at an altitude of 300-1700m. It prefers loose, fertile, well-drained, and acidic to neutral soil with a higher content of humus. It can generally grow in mountain soil and yellow-red soil. Thick magnolia is a light-loving tree species that prefers cool and moist environments with abundant sunlight. It is afraid of severe cold, excessive heat, and water accumulation. The growth period requires an average annual temperature of 16-17℃, a minimum temperature not lower than -8℃, an annual precipitation of 800-1400mm, and a relative humidity of over 70%.
The seed coat of thick magnolia is thick, hard, and contains oil and wax, making it difficult for water to penetrate. It has a long germination time and a low germination rate. Therefore, defatting treatment is necessary during seed sowing and seedling cultivation. Otherwise, the seeds cannot germinate in time after sowing, and sometimes they may not germinate until 1 year later, resulting in uneven seedling emergence. Therefore, defatting treatment of the seeds is an essential step in seedling cultivation.
2. Growth Characteristics of Thick Magnolia
Thick magnolia prefers a cool and moist climate, and high temperatures are not conducive to its growth and development, and it is prone to diseases. It is mostly planted in mountainous areas at an altitude of around 800-1700m. In lower altitudes, seedlings grow faster, while adult trees grow slower. In higher altitudes, seedlings grow slower, while adult trees grow faster. In mountainous areas above 1700 meters, although it can grow, it is difficult for the seeds to mature.
Concave-leaf thick magnolia prefers a warm and humid climate and is generally cultivated in areas below 600m. During the seedling stage, it prefers a semi-shade environment, while adult trees prefer sunlight. The soil should be loose, fertile, and rich in humus, with a neutral to slightly acidic sandy loam being ideal. Heavy clayey soil with poor drainage is not suitable for planting.
Thick magnolia usually sprouts in early May. Leaves and flowers grow and bloom simultaneously in late May. The flowering period lasts for about 20 days, with the flowers opening for 3-4 days. The fruits mature and split in September, and the leaves start to fall in October. Thick magnolia trees grow fastest in height and thickness at 5-6 years old, and the growth becomes less noticeable after 15 years. The bark grows heaviest at 6-16 years old and becomes less noticeable after 16 years. It enters the fruiting period after 20 years, with flowering occurring from April to May and fruit ripening from September to October.
Thick magnolia is a tree species unique to mountainous areas. It prefers a mild, humid climate with frequent rain and fog, and it is afraid of heat but resistant to cold. It can tolerate 3 months of snow cover in winter, and the absolute minimum temperature of -10℃ will not cause freezing damage. If cultivated in regions with temperatures above 38℃ in summer, its growth will be extremely slow, and the height of a 20-year-old tree will be less than 1.5m.
3. Suitable Cultivation Areas in China
Due to the growth characteristics of thick magnolia, it is mainly distributed in the eastern, southern, southeastern, and southwestern parts of China, with fewer in the northeast and northern parts. Currently, the main regions for wild and cultivated thick magnolia are Sichuan, Hubei, Hunan, Jiangxi, Zhejiang, Jiangsu, Fujian, Guizhou, Guangxi, Yunnan, Anhui, Shandong, Henan, Shaanxi, Gansu, and other provinces.
