Houpo is a common and precious Chinese herbal medicine, and the main part used in medicine is the bark. The older the houpo tree, the thicker the bark, the more oily it is, and the higher the yield and quality. Therefore, when harvesting houpo, it is best to choose plants that have been grown and cultivated for more than 15 years. Let's take a look at the time and methods of houpo tree harvesting.
1. Harvesting time
The harvesting time is divided into spring, summer, and winter. The houpo harvested in spring is called "chunpo", the houpo harvested in summer is called "xiapo", and the houpo harvested in winter is called "dongpo".
(1) Chunpo
"Chunpo" refers to the houpo collected from early March to mid-April before flowering. At this time, the bark is rich in nutrients and easily separates from the woody part, making it easy to collect and of good quality.
(2) Xiapo
During the peak flowering period from May to July, the medicinal leaves are lush. At this time, the tissue between the bark and the woody part is loose, making it easy to peel. The bark collected during the period from May to July, when the flowers are in full bloom and the leaves are lush, is also good.
(3) Dongpo
"Dongpo" refers to the houpo collected generally from August to October. The bark of dongpo is rough and of lower quality compared to chunpo and xiapo.
2. Harvesting methods
(1) Tree cutting method
This method is the traditional way of collecting houpo, where the houpo tree is cut down at a height of 15-20 centimeters from the ground. The stem bark and branch bark are peeled in segments of 80-120 centimeters. The root bark is peeled from the exposed roots. The tree cutting method causes serious damage to wild resources and is generally not recommended and should be prohibited. When the artificially planted trees are densely grown for a certain period of time, the tree cutting method can be used, but the roots should not be dug. Instead, new shoots can be used as mother plants for regeneration.
(2) Leaving tree ring stripping method
According to the harvesting time, select trees between 18 and 26 years of age with strong growth. It is best to perform ring stripping on cloudy days or before 8 am and after 4 pm when the air humidity is between 65% and 85%. Take a section of the trunk that is 35-45 centimeters long, 10-20 centimeters above the ground, and open 2-3 long windows with a ring stripping knife at the upper and lower ends. The depth should be close to the cambium. Gently pry up the bark from the longitudinal incision and peel it off slowly. After peeling the bark, immediately wrap it with transparent plastic film. When wrapping, make sure to tighten the upper part and loosen the lower part to minimize the contact between the film and the woody part. During the ring stripping process, avoid touching the cambium with fingers to prevent necrosis caused by contact and infection.
After peeling the bark for 26-37 days, new bark will grow in the peeled area. After 45 days, the plastic film can gradually be removed. In the following spring, the bark can be peeled again at other parts of the trunk during the harvesting season. This method is scientific and does not require tree cutting, ensuring the sustainability of resources.
3. Harvesting according to different parts
Harvesting houpo should be done according to the specifications and commercial requirements to achieve the desired quality. Random harvesting will not meet the specifications. The following are the different specifications of houpo harvesting:
(1) Tongpo (stem houpo or dry houpo)
Tongpo refers to the bark harvested from the main stem (trunk) of houpo, which can be called "stem houpo" or "dry houpo". After harvesting, it resembles a rolled tube, hence the name "tongpo".
Harvesting tongpo: Select the main stem (trunk) of houpo, cut the bark into segments of 70-90 centimeters long, starting from the lower part of the trunk and peeling the bark section by section. Naturally roll them into tube shapes or double tube shapes. Place them flat in a container to avoid the loss of sap from the cut ends of the bark, which may affect the quality.
(2) Xiepo (root houpo)
Xiepo is the bark harvested from the lower part near the roots. Peel the bark from 5-8 centimeters above the base of the trunk, up to 35-70 centimeters, and open it like a trumpet mouth at the end near the roots. It resembles a boot, hence the name "xiepo".
(3) Jichangpo (root intestine houpo)
Jichangpo refers to the bark harvested from the roots of houpo, which is then processed into single or double rolls or irregular pieces. It is often split and bent like a chicken intestine, hence the name "jichangpo". The length is 15-45 centimeters and the thickness is 1-4 millimeters. Nowadays, harvesting the roots is generally not recommended, and it is better to leave some stumps without digging the roots for propagation and regeneration.
(4) Zhipo (branch houpo)
Zhipo refers to the bark harvested from the thick branches. The harvesting method is the same as for dry houpo. It is generally in the form of thin single tubes, 15-25 centimeters long and 1-3 millimeters thick.
(5) Ponaohou (brain houpo)
Select the part of the trunk that is 60 centimeters above the ground, make a horizontal cut or saw through the bark, and then make a vertical cut to peel off the bark at a depth of 3-8 centimeters into the soil. This is called "ponaohou".
