Polygonatum cultivation techniques explained: key points in one article

I. Morphological characteristics

Polygonatum is a perennial herbaceous plant of the Liliaceae family. The rhizome creeps horizontally, is thick and fleshy, yellowish-white, and slightly flattened-cylindrical in shape. It has several stem scars, which are relatively thick, with the thickest part reaching a diameter of up to 2.5 cm, and bears a few fibrous roots. The stem is erect, cylindrical, single, 50-80 cm tall, smooth and hairless. Leaves are sessile; usually 4-5 in a whorl; leaf blades linear-lanceolate to linear, 7-11 cm long, 5-12 mm wide, apex acuminate and curled, green above, pale green below. Flowers are axillary, nodding, pedicels 1.5-2 cm long, forked at the apex, bearing 2 flowers; bracts small, much shorter than the pedicels; perianth tubular, 8-13 mm long, white, apex 6-toothed, tinged greenish-white; stamens 6, inserted at the middle of the perianth tube, filaments smooth; pistil 1, equal in length to the stamens, ovary superior, stigma covered with white hairs. Berry spherical, 7-10 mm in diameter, black when ripe. Flowering period May-June. Fruiting period June-July. It grows on barren hillsides and at the edges of mixed wood forests or shrub thickets in mountainous areas.

II. Pharmacological effects

Polygonatum is sweet in flavor and neutral in nature, and has the effects of nourishing the kidneys and moistening the lungs, and tonifying the spleen and supplementing qi. It is often used to treat dry cough and consumptive cough, poor appetite and fatigue, soreness and weakness of the waist and knees, dizziness, and premature graying of hair and beard caused by yin deficiency and lung dryness, weak spleen and stomach, and kidney deficiency with essence depletion. For winter health tonification, the key is to nourish yin and replenish essence, and benefit the lungs, spleen, and kidneys, so Polygonatum is the most suitable choice. In addition to medicinal tonification, Polygonatum is also very useful in dietary therapy. Li Shizhen once said in the Compendium of Materia Medica that “Polygonatum is an essential medicine for consumption.”

III. Cultivation techniques

1. Site selection and land preparation: Choose a moist plot with sufficient shade. The soil should preferably be loam or sandy loam with a loose texture and good water-holding capacity. Before sowing, deep plow once, and during land preparation apply 2000 kg of farmyard manure per mu, plow it into the soil as base fertilizer, then rake fine and level, and make beds 1.2 m wide.

2. Propagation methods

A. Rhizome propagation: In late autumn or around late March in early spring, select healthy, pest- and disease-free rhizomes from 1-2-year-old plants, take the young tender parts at the apex, cut them into several sections, each with 3-4 nodes, let the wounds dry slightly, and plant them at a row spacing of 22-24 cm, plant spacing of 10-16 cm, and depth of 5 cm. After covering with soil, press lightly and water. Thereafter water once every 3-5 days to keep the soil moist. When planting in late autumn, cover the soil surface with some barnyard manure and grass for warmth.

B. Seed propagation: After the seeds mature in August, select mature and plump seeds and immediately carry out sand storage treatment: mix 1 part seeds with 3 parts sandy soil evenly. Store in a pit 30 cm deep in a shaded place and keep moist. Wait until late March of the following year, sieve out the seeds, evenly broadcast them in shallow furrows on the bed surface at a row spacing of 12-15 cm, cover with about 1.5 cm of soil, press lightly, water, and cover with a layer of grass to retain moisture. Remove the covering grass before emergence. When the seedlings are 6-9 cm tall, thin them appropriately where too dense, and transplant after 1 year. To meet the shade conditions required for Polygonatum growth, corn can be planted on the bed ridges.

3. Field management: In the early growth stage, cultivate and weed frequently, once each in April, June, September, and November every year. Shallow hoeing is appropriate, along with appropriate hilling; in the later stage, just pull weeds. If drought occurs or if planted in a relatively sunny and dry place, timely watering is needed. Each year, combine cultivation and weeding with topdressing. After the first 3 cultivations, apply 1500 kg of farmyard manure per mu, mix evenly with 50 kg of superphosphate and 50 kg of cake fertilizer, open furrows between the rows and apply, then cover with soil to cover the fertilizer.