Hou Po is a valuable medicinal plant in China. Its bark, root bark, flowers, seeds, and buds can all be used as medicine, but the bark is the most commonly used. It has the effects of eliminating dampness, promoting qi circulation, resolving phlegm, and relieving pain. Hou Po trees need to grow for more than 20 years before they can be cut and the bark can be harvested. Due to the long growth period of Hou Po, it has a rich medicinal value, making it a scarce resource in China. Therefore, China has already implemented protection measures for Hou Po as a precious resource.
1. Transplanting
1. Selection of Transplanting Site
Based on the growth habits and characteristics of Hou Po, the site for transplanting should be located at an altitude of 800-2200 meters, have fertile soil with a neutral to slightly acidic pH, deep and loose soil, good air permeability, and good drainage on a sunny slope.
In addition, Hou Po can be sporadically cultivated in mountainous areas, along rural roadsides, field corners, and around houses. It can also be planted in urban areas, parks, scenic areas, and green belts, serving both as a greening agent for villages and a resource for Hou Po.
2. Transplanting Time and Method
Transplanting Hou Po is usually done in late autumn or early winter (late October to early November) after the leaves have fallen, or in spring around the Qingming Festival (late March to early April). The survival rate is higher during these times. For large-scale afforestation, the selected slope needs to be leveled, and the planting area should be cleared of weeds, rocks, vines, thorns, and dead tree stumps, and sources of pests and diseases should be eliminated.
After clearing the area, dig holes (pits) with a spacing of 3 meters between plants and 2.5 meters between rows. The hole width (diameter) should be 70 centimeters and the depth should be 35 centimeters. Plant one seedling per hole, hold the seedling in the middle and plant it in the center of the hole, spreading the roots in different directions without bending them. Then, fill the hole with fine soil, gently press it down with your foot when the soil depth is 8 to 12 centimeters, and water it thoroughly to establish the roots.
3. Seedling Collection
When digging up young seedlings for transplanting, be careful and meticulous. Dig deep from one end of the seedbed, about 35 to 45 centimeters deep, and dig in order, taking care not to damage the young seedlings and roots. Take as many seedlings as needed. For seedlings that need to be transported to a distant location for cultivation, the roots should be covered with mud and wrapped in straw, and placed in wooden boxes to ensure their moisture content.
After transplanting, the seedlings should be watered regularly to keep the soil moist. Once the planted seedlings have established, watering can be reduced and the interval between waterings can be extended.
2. Seedling and Planting Management
1. Seedling Management
(1) Spring-sown Seedling Management
After sowing the seeds, the soil in the seedling area should be kept moist, and regular watering should be done to replenish water when it becomes dry. In the rainy season, waterlogging should be avoided to prevent root rot. Weeds should be pulled and the soil should be loosened regularly. Fertilization should be done multiple times in small amounts.
Fertilization should be done 2-4 times a year, with organic fertilizers as the main source and chemical fertilizers as a supplement.
The density of Hou Po seedlings per acre should be around 20,000 plants, so the sowing amount per acre should be around 4-4.5 kilograms. If the seeds are of good quality with a high germination rate, the dry weight per acre should be around 3.5-4.5 kilograms, and the fresh weight should be around 8-12 kilograms.
(2) Autumn-sown Seedling Management
Autumn sowing, also known as winter sowing, is done from mid-October to early December, with the best time being around the beginning of winter. After sowing, the seeds undergo wintering in the seedbed. In addition to covering them with fine soil, they should also be covered with rice straw, tree branches, pine needles, or straw with a thickness of 3-5 centimeters to maintain soil temperature and prevent freezing of the seeds in the ground, which would affect germination.
Around the Qingming Festival of the following year, when the seeds have sprouted, the covering straw on the Hou Po seedbed should be uncovered, or the covering straw can be burned before the seeds sprout. Burning the straw can increase soil temperature and promote even germination without being affected by diseases. Weeding should be done regularly during the seedling stage, and watering should be done in the morning and evening during dry periods to keep the soil moist. Other management practices are the same as for spring-sown seedlings.
(3) Mulch Seedling Management
For mulch seedlings, the temperature of the soil should be checked regularly, acidity should be removed, and ventilation and normal soil temperature should be maintained. After the seedlings have sprouted, the mulch should be removed during the day to expose the seedlings, and the mulch should be covered at night for heat preservation. This process should be repeated for 5-7 days. After removing the mulch, intertillage and water drainage should be done. After weeding, ashes or fertilizers can be applied to promote the growth of the seedlings. Other management practices are the same as for spring-sown seedlings.
2. Plant Management after Transplanting
After transplanting Hou Po seedlings on a slope, management should not be neglected. Regular watering should be done until the seedlings have established. In the initial 3-6 years after transplanting, fertilization, weeding, and loosening of the soil should be done 2-3 times a year. If there is less rain or a dry season, watering should be done. Grazing is strictly prohibited in Hou Po planting areas to prevent damage to the seedlings and plants by cattle and sheep. Observation should be done regularly, and if pests are found, timely prevention and control measures should be taken.
In spring, the soil should be loosened, weeds should be removed, and manure, ash, or organic fertilizers should be applied. Additional amounts of superphosphate and sulfuric acid can also be applied to promote the rapid growth of Hou Po.
At the end of spring and in early summer, the area around the Hou Po trees should be cleaned, weeds should be removed, and vines, thorns, and sources of pests and diseases should be eliminated. In the first 3 years after transplantation, when the weeds grow vigorously in the summer, weeding and soil loosening should be done, and the surrounding area should be cleared of vines and grasses. After 4 years of growth, intertillage and soil cultivation can be done every two years. Care should be taken not to damage the root system during weeding and soil cultivation.
For Hou Po trees that have grown into forests after 10 years, weak branches, dead branches, drooping branches, and excessively dense branches or diseased branches should be pruned. This promotes ventilation, appropriate light exposure, and concentrated nutrient supply to the main trunk and main branches, which is beneficial for the growth of Hou Po. Excessively dense crowns should be thinned or transplanted.
3. Three-dimensional Planting of Hou Po Forests
(1) Medicinal Crop Intercropping
Since it takes at least 10 years from planting to harvesting medicinal parts of Hou Po due to its long growth cycle, in order to fully and rationally utilize land resources and increase economic benefits, three-dimensional planting can be adopted for Hou Po, integrating medicinal crops and short-term crops. It can be intercropped with other medicinal herbs that have certain economic benefits, a short growth period, and quick results, such as Bai You, Chai Hu, Huang Quan, Fang Feng, Sha Shen, Huang Jing, Zi Dan Shen, Xiao Hong Shen, Chong Lou, and Dang Gui. Hou Po can also be intercropped with coniferous trees for mixed afforestation. Chinese fir is one of the companion tree species of Hou Po. Planting Hou Po with Chinese fir has mutual promotion effects and can reduce the occurrence of pests and diseases. Therefore, when planting Hou Po forests, high-value medicinal coniferous tree species such as Pinus armandii, Incense cedar, Taxus chinensis, and Pinus henryi, as well as economically valuable timber tree species, can be selected.
(2) Intercropping with Cash Crops
Before the Hou Po forest canopy becomes dense after 5-6 years of growth, it can be intercropped with economic crops such as beans, potatoes, peanuts, Chinese yam, and sesame. By managing the intercropped cash crops, including weeding, loosening the soil, and fertilizing, the growth of the Hou Po forest during its early stage can also be promoted.
