How to grow black cohosh? Detailed explanation of planting techniques and management methods

Seed harvesting and treatment

Because black cohosh has a long flowering period, the seeds mature over varying lengths of time. When the fruit ripens, the valves split open naturally and the seeds scatter with the wind. Therefore, they must be harvested as they ripen. When the fruit begins to turn yellow from green, the skin starts to dry out and the valves are about to split, cut off the seed spikes. After drying in the sun, the skin splits open completely; remove the skin and impurities, and after the seeds are dried again in the sun, they can be sown in autumn. If sowing in spring the following year, mix the seeds with fine sand at a ratio of 1:3 for sand storage, water to keep moist, and store outdoors at low temperature. Note that old seeds from the previous year must not be used in cultivation, because after harvesting, if the seeds are stored dry indoors for 2 months, the germination rate is below 10%, and after one year of storage most will not germinate.

Sowing

Both spring and autumn are suitable. In spring, it is from late March to mid-April. When sowing, first open furrows along the bed with a row spacing of 20--25 cm, with a furrow depth of 4-5 cm, sow the seeds evenly in rows in the furrows, cover with 1.5-2 cm of fine soil, press down lightly, and when the soil is dry, water once thoroughly with a watering can, then cover the bed surface with a layer of straw to retain moisture. In autumn, it is from mid-October to early November, and the sowing method is the same as in spring.

For spring sowing, when the temperature is 15-20 degrees, seedlings emerge in 18-20 days. Remove the straw from the bed surface gradually, keep the seedbed soil moist, and in dry conditions water with a watering can in the morning and evening. Because the seedlings are afraid of strong light, use a simple reed curtain to shade the upper part of the bed. After the seedlings have grown for 1 year, transplant them. The transplanting time is after the aboveground parts wither in autumn or before they turn green in spring. In the prepared field, open holes with a plant spacing of 30 cm and a row spacing of 45 cm, with a hole depth of 15 cm, plant 1 seedling per hole, and cover with soil to a depth of 4-5 cm above the terminal bud, then water once thoroughly after planting.

Field management

In dry spring weather, water to maintain moisture. During the growing period, loosen the soil and weed frequently. Two-year-old black cohosh bears fewer fruits and the seed quality is poor. To avoid affecting rhizome growth, the inflorescence should be cut off at the early bud stage, and in July-August, before the rainy season arrives, earth up appropriately. If drought occurs, water in time to keep the soil moist and promote seedling growth. During the seedling stage, cultivate and weed frequently, and hoe shallowly to prevent damaging the rhizome. At the same time, in combination with loosening the soil and weeding, apply an appropriate amount of nitrogen fertilizer in June-July according to seedling growth. Two-year-old black cohosh bears fewer fruits and the seed quality is poor; at the early bud stage, the inflorescence can be cut off to favor rhizome growth. After that, cultivate and weed 1-2 times each year. In the rainy season from July to August each year, earth up appropriately around the roots to prevent water accumulation. This is because in the hot, rainy summer season, many plants wither and die from root rot.

Pest and disease control

Black cohosh has very few pests and diseases, with only a small number of white grubs, which mainly damage the rhizome, generally occurring in May-June. They can be controlled by watering the roots with 800-times 40% dimethoate emulsifiable concentrate. Among diseases, there is gray leaf spot, which damages the leaves and occurs in August-September. Before onset, spray Bordeaux mixture at 1:1:120 dilution for prevention, and in the early stage of the disease, use 65% zineb at 500 times dilution for control.

Harvesting and processing

Cultivated black cohosh can be harvested after 4 years of growth, and the harvest season is mainly in autumn. When harvesting, choose a sunny day, first cut off the withered branches, stems and leaves of the aboveground part, dig out the rhizome, remove the soil, wash it clean, and when it is 80% dry, burn off the fibrous roots with fire, then dry it completely in the sun, and knock off the outer skin and remaining fibrous roots. It can be packed in gunny sacks, about 20 kg per piece, and stored in a dry, ventilated place.