When is the best time to plant Bupleurum? How to plant?

Bupleurum is a plant with strong drought resistance and does not have strict requirements on soil conditions. During the seed germination stage, it is necessary to ensure that the soil has appropriate moisture. During the growth cycle of Bupleurum, additional watering is usually not required unless extreme drought conditions occur. Mainly water moderately during the critical period of water and nutrients and after fertilizing to meet its growth needs. Bupleurum cannot tolerate waterlogging during its growing season. In the seedling stage of Bupleurum, it prefers a moist and cool environment; and when the plant grows up, in order to ensure its normal growth and development, it needs sufficient sunlight. Proper light intensity and time are essential for the healthy growth of Bupleurum chinense. Insufficient light may prolong its growth cycle. So when is the best time to plant Bupleurum? How to plant?

1. Land Selection and Preparation

1. Land selection

Bupleurum prefers warm and humid climatic conditions and is drought-resistant and cold-resistant, but does not like stagnant water and high temperature environments. Its soil requirements include good drainage, fertility, looseness and depth. The most suitable soil types are sandy soil, sandy loam and humus soil, and the soil pH should be controlled between 6.5 and 7.5.

2. Land consolidation

Because Bupleurum seeds are small and belong to the rhizome type of medicinal material, deep plowing and careful raking are required when preparing the planting site, and appropriate amounts of fertilizer are applied. Usually, 30 kg of superphosphate and 3,000 kg of mixed fertilizer are applied per mu of land. After spreading evenly, deep plowing is carried out into the soil to ensure that the ground is level. High ridge planting and deep plowing can help increase the yield of Bupleurum. Deep plowing can enhance the soil's ability to retain fertilizer and water, and loose soil is conducive to root growth and nutrient absorption; high ridge planting can help increase the surface temperature, reduce the temperature difference between day and night, and promote the growth of Bupleurum.

2. Seed treatment

The flowering and fruiting period of Bupleurum is relatively long, from July to October each year, so the maturity and size of the seeds will vary. The germination rate is about 50%, and germination begins about 25 days after sowing. Proper seed treatment can effectively improve the germination rate.

There are three main seed treatment methods:

① Chemical treatment: Soak the seeds in 1% potassium permanganate solution for 10 minutes and wash before sowing.

②Hormone treatment: Soak the seeds in 0.5mg/kg cytokinin solution for one day, then wash and sow.

③Sand storage treatment: Soak the seeds in warm water at 30℃ to 40℃ for one day. After removing the shriveled seeds, mix them with wet sand in a ratio of 1:3. Germination should be carried out in an environment of 20℃ to 25℃. After about 15 days, most of the seeds will crack and can be sown together with wet sand. The sowing time is usually from March to early May in spring and from October to before the soil freezes in autumn, and the sowing rate is 2.5 to 3.0 kg per mu.

3. Planting technology

1. Sowing time

Spring sowing: Soil surface temperature is stable at above 10℃ or the soil is thawed more than 10cm.

Summer sowing: also known as rainy season sowing, suitable for areas with spring drought or no irrigation conditions.

Autumn sowing: It is better to sow early rather than late, generally in early to mid-August, and seedlings will emerge in the same year after sowing.

2. Sowing method

The sowing amount is 2 kg per mu, the row spacing is 25 cm, the furrow depth is 2 cm, and after even sowing, cover with 0.5 cm of soil and compact it, and cover with grass to keep it moist. Before germination, the soil needs to be kept moist and watered in time. In addition, Bupleurum can be intercropped with cereals or oil crops , and the straw can be cleaned after the crops are harvested, which is beneficial to field management. Intercropping technology has the advantages of improving land utilization, protecting seedlings and saving manpower time.

4. Field Management

1. Thinning out seedlings

This should be done when the seedlings grow to 10cm, and the spacing between rows and plants should be controlled at 10cm and 15cm, followed by timely irrigation.

2. Control stems and leaves, promote root system, and top

Bupleurum is a rhizome medicinal material, so it is necessary to strengthen stem control and root promotion, and pay attention to soil cultivation and weeding at the roots. When the plant is 40cm tall, top it and remove the overgrown stems and buds to improve quality and yield. Avoid rainy days when topping. It is best to do it after the dew has dried or in the afternoon.

3. Loosening the soil

Regularly till the soil to promote deep rooting, reduce branching and increase thickness. During the growing season, the soil generally needs to be tilled four times, especially after rain and during drought.

4. Topdressing

Apply fertilizer at least once during the growing period, usually when the soil is first ploughed, with an application rate of 20 to 25 kg per mu. Avoid using diammonium fertilizer or urea.

5. Harvest

The harvesting and processing of Bupleurum chinense includes the collection of its stems, seeds and medicinal roots. When the seeds appear yellow-black and the leaves have completely turned yellow, the stems and seeds can be cut and then threshed. The stems and seeds are dried separately and stored properly for later sale.

As for harvesting the medicinal roots, it is usually recommended to do so two years after planting. When harvesting, deep manual digging should be used to ensure that all roots are dug out completely to avoid direct pulling out which may cause root breakage, thus affecting yield and profit. The dug roots need to be sorted and arranged according to size, ensuring that each bunch is of uniform size and neat, and then tied into small bundles for drying. They can be sold after drying.

The above is an introduction to the planting time and methods of Bupleurum. When planting Bupleurum, you must first consider whether the environment is suitable. If it is not suitable, do not plant blindly to avoid affecting the yield.