How to Grow Rhodiola sachalinensis? A Complete Guide to Cultivation Techniques
RhodiolasachalinensisThe dried roots and rhizomes of Rhodiola sachalinensis A. Bor., a perennial herb in the Crassulaceae family, also known as Sakhalin rhodiola. It has relatively ideal effects in resisting fatigue, resisting aging, tonifying and strengthening the body, improving work efficiency, and acting as an adaptogen. The above-ground parts are also used medicinally. It is mainly produced in the Changbai Mountain area of Jilin Province and in Shangzhi, Hailin, Ning'an and other counties of Heilongjiang Province. At present, large areas of artificial cultivation already exist in the mountainous areas of the three northeastern provinces.
(1) Morphological Characteristics
Perennial herb, flowering stems erect, unbranched, plant height 15-30 (-39) cm, number of flowering stems per plant 40-70, with the maximum being more than 300, growing in clumps. Leaves simple, alternate, leaf blades oblong or oblong-spatulate to oblong-lanceolate, sessile, leaf blades 1-5 cm long and 0.4-1.3 cm wide, base cuneate, apex very acute or gradually acuminate, margin coarsely serrate, lower part nearly entire. Cyme terminal, dense and many-flowered, peduncle 5-6 cm long, pedicels 0.3-0.5 cm long, with bracts below. Dioecious or polygamo-dioecious, sepals 4, petals 4 (rarely 5), yellow or yellow-green, linear-lanceolate or oblong, 3-6 mm long, apex obtuse; in male flowers stamens 8, longer than petals, of which 4 are inserted at the base of the petals and slightly longer than the petals, anthers round, bright yellow after opening. The middle part of the flower has 3-4 degenerated carpels, mostly sterile, a few developing into fruit. At the base of the petals there are 4 oblong orange-yellow nectaries; female flower petals yellow-green, slightly narrower than those of male flowers, apex slightly pointed, carpels 4 (rarely 5) erect, gray-green, styles recurved, scales 4, glandular, oblong, apex emarginate. Follicles lanceolate, erect, 6-8 mm long, beak 1 mm long, fruit brown or brownish when mature; seeds oblong or lanceolate, brown or light brown, about 2 mm long. Flowering period June-July, fruiting period late August. After artificial cultivation, the flowering and fruiting period is about 1 month earlier than in the wild.
(2) Growth Habits
Wild Rhodiola sachalinensis has strong adaptability and can grow and develop normally under the very harsh natural conditions of high-altitude mountainous areas, with a growth period of 70-80 days. It prefers a warm and cool climate, is resistant to severe cold, tolerant of low temperatures, tolerant of drought, afraid of waterlogging, and avoids the high-temperature and high-humidity climate of summer.
The seeds are very small, with a 1000-seed weight of 0.13-0.14 g, and have incomplete dormancy characteristics. The suitable germination temperature is 15-20°C, and seedlings begin to emerge when the surface temperature reaches 10°C in early spring. After the seeds are stored at room temperature for 1 year, most lose their germination ability. Stored under low-temperature conditions below 0°C for 2 years, they still maintain a good germination rate.
Under suitable conditions, seedlings emerge 5-7 days after sowing. In the early stage, seedlings grow slowly, prefer moisture, tolerate low temperatures, and avoid strong light. After the above-ground stems grow out, growth accelerates, and they tolerate drought and prefer light. One-year-old seedlings are 7-10 cm tall, and a few plants flower sparsely; two-year-old seedlings are 10-15 cm tall, and most flower and set seed.
(3) Cultivation Techniques
1. Site selection and land preparation Rhodiola sachalinensis does not have very strict soil requirements. Mountainous areas with relatively high altitude, a cool climate, a short frost-free period, and a relatively large diurnal temperature difference in summer should be selected for cultivation. Plain areas at low altitude, areas with high temperature and much rain in summer, and areas with a long frost-free period are not suitable for cultivation. Specifically, the cultivation site should be selected as loam or sandy loam with much humus, deep soil layers, sufficient sunlight, and good drainage. Forest cutting sites or virgin wasteland in mountainous areas can be used for cultivation, and in the northeastern region, old ginseng land can also be used for cultivation. The seedling-raising site is best selected as a plot with fertile and loose soil and relatively close to a water source. For the transplanting site, try to choose hillside land with good drainage and slightly more sand in the soil. Clay soil, saline-alkali soil, and low-lying waterlogged land are not suitable for cultivation.
After selecting the site, plow deeply 30-40 cm, remove debris from the field, break up clods, and make beds along the slope direction, with bed width 1-1.2 m and height 20-25 cm, and operation paths 50-70 cm wide. Generally no fertilizer is applied. If the soil is too barren, an appropriate amount of decomposed farmyard manure may be applied, but no chemical fertilizer. If old ginseng land is selected for cultivation, the soil should be disinfected before sowing.
2. Propagation methods In production, seed propagation is mainly used, with concentrated seedling raising in the first year, transplanting in the second year, and harvesting after 4 years of growth. Next is rhizome propagation, with harvesting after 2 years of growth.
(1) Seedling raising Select fresh mature seeds and sow them in spring or autumn. Spring sowing time is from late March to early April, and autumn sowing is from mid-October until before freezing. Autumn sowing results in earlier emergence and complete seedlings, and the seeds do not need treatment. When sowing in spring, the seeds should be soaked in water. The specific method is to put the seeds together into a clean cloth bag, place the bag in ordinary water and soak for 40-50 hours, changing the water 2-4 times a day. After soaking, air-dry the seeds in a cool, ventilated place to remove surface moisture, and sow immediately when the seeds can naturally separate. When sowing, first use a wooden board to scrape the surface soil of the seedling bed flat, open furrows across the bed at a row spacing of 8-10 cm, with a furrow depth of 3-5 mm, evenly scatter the seeds in the furrows, with a sowing rate of 1.5-2.0 g per sq m, cover with 2-3 mm of sieved fine soil, press the soil firm with the hand or a wooden board, and then cover the bed surface with a layer of rice straw or pine branches to retain moisture.
(2) Transplanting Transplant after the seedlings have grown for 1 year. The transplanting time is after the above-ground parts wither in autumn of that year or before greening up in spring of the following year. Spring transplanting gives better results, generally from late March to early April when the seedlings have not yet sprouted. First dig out all the seedlings, grade them according to seed-stock size, and transplant them separately. Planting row spacing is 20 cm and plant spacing is 10-12 cm. Open furrows across the bed with a furrow depth of 10-12 cm, place the seed stock into the furrow with the terminal bud facing upward, and the soil covering thickness should preferably be 2-3 cm above the terminal bud. After planting, press lightly. If the soil is too dry, water after planting. Plant about 50 large seedlings per sq m, and small seedlings can be planted at 60 per sq m.
(3) Rhizome propagation Collect wild rhizomes or cut off large rhizomes as seed stock at harvest time. First cut the rhizomes into 3-4 cm long rhizome segments, air-dry them in a cool place for 4-6 hours to heal the cut surface of the seed stock, then plant according to the time and method in the transplanting section above. When planting, place the rhizome segments obliquely in the furrow with the terminal bud facing upward, cover with a thickness of 5-6 cm, and press appropriately after planting. The survival rate is generally above 95%.
3. Field management
(1) Seedling-raising land In the early stage after the seedlings emerge, growth is slow. Seedlings 20 days after emergence still have only 2 cotyledons, and the plants are very small. At this time, weeds grow relatively quickly, so weeds in the field should be removed in time. During the seedling stage, keep the bed soil moist at all times, and when dry, water the bed surface at any time with a fine-hole watering can. When emergence begins, remove the straw covering the bed surface gradually in the morning or evening so that the seedlings receive appropriate light. After the above-ground stems grow out, according to the emergence situation, thin out overly dense seedlings or transplant them elsewhere.