Glehnia Planting Methods and Technical Key Points

Biological characteristics

Glehnia is a herbaceous plant with strong adaptability; it prefers a warm, humid climate, is drought-resistant and cold-tolerant, and prefers sandy soil. It is averse to waterlogging, continuous cropping and strong sunlight.

Apart from the seedling stage and seed-production fields kept for seed, which need sufficient water, the later growth stage is not suited to much watering. The best preceding crop is root and tuber crops. It is averse to soybean and peanut crops; seed germination rate drops markedly after one year, and by the third year the seeds lose their germination capacity. Glehnia seed sown in winter has a high germination rate and emerges evenly. Seed sown in winter emerges around Guyu (Grain Rain) the following year, generally does not flower or fruit, and only flowers and fruits in the third year. Sown in spring the following year, the germination rate drops markedly; it flowers and fruits only in the second year, bolts after Xiaoman (Lesser Fullness), flowers within a week, with a flowering period of half a month, and the seeds mature around Toufu (the first fu period).

Site selection and land preparation

Choose relatively moist, well-drained sandy loam rich in humus; apply 60000 kg of barnyard manure and 750-1500 kg of cake fertilizer per hectare as base fertilizer, plus 7.5 kg of trichlorfon, and turn into the soil to a depth of 40-50 cm; work the soil fine and rake it level, and make flat beds or raised beds 3-6 cm wide.

Propagation methods

Glehnia is a deep-rooted plant, so before sowing the soil must be deeply ploughed and raked level. Before sowing, remove the fruit wings from the seeds, soak them in 25-degree warm water for 4 hours, take them out and cool slightly, mix with 2/3 moist sand, place in a box and freeze; sow after thawing in spring. For autumn sowing, sow before the ground freezes. Spring-sown seed should not be treated by sand storage, otherwise it will not emerge that year.

(2) Sowing methods

For autumn sowing, draw shallow furrows half a cm deep at a row spacing of 5-6 cm; sow seeds 4-5 cm apart, cover with soil and water, then cover with rice straw; before the ground freezes, water heavily once more and cover with a layer of pen manure. For spring sowing, do it around Qingming (Pure Brightness) to Guyu (Grain Rain), by the same method. If the seed is not treated with low-temperature freezing, it will not emerge after sowing; if untreated, it is best to sow immediately after harvest. On sandy loam the sowing rate is 75 kg per hectare; on pure sand 90-112.5 kg per hectare; on fertile soil with irrigation conditions 52.5-60 kg per hectare. After sowing, on pure sand press with yellow mud or small broken stone to prevent wind blowing the sand and causing losses; in waterlogged lowland, press with sand when the ground freezes. Autumn-sown seed emerges in March of the following year.

(3) Field management

After the ground thaws, if the soil is compacted, loosen it and conserve moisture; pull weeds as soon as they appear. When the seedlings have about 3 true leaves, thin them, leaving them in a triangular arrangement with a plant spacing of about 0.7 cm; they must not be too sparse, otherwise the roots will fork, and if too dense they will grow poorly. Water as appropriate during spring drought to keep the ground moist. In the later growth stage the ground must not be waterlogged; remove buds promptly when they appear at the seedling stage. For two-year-old glehnia, apply farmyard manure in spring, and in May apply chemical fertilizer once in combination with irrigation.

Pest and disease control

(1) Root-knot nematode disease

This disease is prone to occur in May, when nematodes invade the root tips, suck the sap and form root galls, causing seedlings to turn yellow and die.

Control methods: avoid continuous cropping and choose disease-free land. Disinfect the soil with DD mixture at 450-750 kg per hectare. Method: 20 days before sowing, when the ground temperature is above 15 degrees C, open furrows about 30 cm wide and 6-7 cm deep, apply the pesticide into the furrows, then cover with soil and press firm.

(2) Rust disease

Also called jaundice disease, it begins to occur from mid to late July; reddish-brown lesions appear on stems and leaves, and at the late stage the lesion surfaces rupture, causing the plant to die early.

Control method: after onset, use a 300-fold solution of ferrous dimethyldithiocarbamate (with 0.2% washing powder), once every 10 days.