Detailed Explanation of Motherwort Cultivation Techniques
Motherwort is the dried aerial whole plant of Leonurus japonicus (family Lamiaceae), produced throughout the country and mostly wild. The related species Leonurus macranthus can also be used medicinally. Its seeds are also used medicinally, known as Chongweizi, with the aliases motherwort seed, Kuncǎo seed, and small flax seed. In recent years, small-scale cultivation has been carried out in Beijing, Tianjin, Hebei, and other places. Motherwort is the dried aerial whole plant of Leonurus japonicus (family Lamiaceae), produced throughout the country and mostly wild. The related species Leonurus macranthus can also be used medicinally. Its seeds are also used medicinally, known as Chongweizi, with the aliases motherwort seed, Kuncǎo seed, and small flax seed. In recent years, small-scale cultivation has been carried out in Beijing, Tianjin, Hebei, and other places.
Growth Habits
Motherwort prefers a warm and humid climate and plenty of sunlight. It can grow on plains and slopes where crops are generally cultivated, with relatively fertile soil being best. It needs sufficient water, but should not be waterlogged, as it fears waterlogging.
Cultivation Techniques
Motherwort is divided into early-maturing motherwort and winter-type motherwort. Generally, seed propagation is used, with direct sowing as the planting method. Seedling transplanting is also used, but the yield is lower, only 60% of direct sowing, so it is mostly not adopted.
Seed preparation: Select fresh seeds from the current year with a germination rate generally above 80%. For hole sowing, generally prepare 400-450 g of seed per mu; for drill sowing, prepare 500-600 g of seed per mu.
Land preparation: Prepare the land before sowing. Apply 1500-2000 kg of compost or decomposed barnyard manure per mu as base fertilizer, then plow and harrow finely to level. For drill sowing, make raised beds 130 cm wide; for hole sowing, beds are not necessary, but in all cases, large and small drainage ditches should be opened well according to the terrain and local conditions.
Sowing: Early-maturing motherwort can be sown in autumn, spring, or summer, while winter-type motherwort must be sown in autumn. Spring sowing is best during the period from Yushui to Jingzhe (late February to early March); in the north, summer sowing is used to make use of summer fallow land, sown after wheat harvest at Mangzhong, but the yield is not high; in low-temperature areas, autumn sowing is mostly adopted, best from Qiufen to Hanlu (late September to early October) when the soil is moist. The choice of autumn sowing time directly affects the yield and quality of the product. Too early makes it susceptible to aphid damage; too late means it is affected by low temperatures and dry soil, cannot germinate that year, and can only germinate from Chunfen to Qingming the following spring, with uneven and irregular germination, and mostly cannot bolt or flower.
Sowing is divided into drill sowing, hole sowing, and broadcast sowing. Plains areas mostly use drill sowing, slopes mostly use hole sowing, and broadcast sowing is inconvenient to manage, so it is mostly not adopted. Before sowing, mix the seeds with wood ash or fine soil mixed fertilizer, then mix with human and livestock manure and urine. The moisture level should be such that it can be scattered. Generally, use 250-300 kg of wood ash or soil mixed fertilizer and 35-40 kg of human and livestock manure and urine per mu. For drill sowing, open horizontal furrows in the bed, with a furrow center spacing of about 25 cm, a sowing width of about 10 cm, and a depth of 4-7 cm. The furrow bottom should be flat. Before sowing, apply 2500-3000 kg of human and livestock manure and urine in the furrows, then evenly scatter the seed-ash mixture in, with no need to cover with soil. For hole sowing, open holes with a spacing of about 25 cm between holes and rows, a hole diameter of about 10 cm, and a depth of 3-7 cm. The hole bottom should be flat. First apply 1000-1200 kg of human and livestock manure and urine per mu in the holes, then evenly scatter the seed-ash mixture in, with no need to cover with soil.
Field Management
Thinning and replanting: Begin thinning when the seedlings are about 5 cm tall, then carry out 2-3 more thinnings successively, and finalize the stand when the seedlings are 15-20 cm tall. For drill sowing, keep seedlings in a staggered pattern with a plant spacing of about 10 cm; for hole sowing, keep 2-3 seedlings per hole. If missing plants are found during thinning, transplant and replant promptly.
Cultivation and weeding: For spring sowing, carry out cultivation and weeding 3 times, respectively when the seedlings are about 5 cm, 15 cm, and 30 cm tall; for summer sowing, carry them out at the appropriate time according to plant growth; for autumn sowing, carry out the first cultivation and weeding that year when the seedlings have grown 3-4 true leaves, and carry out cultivation and weeding three more times the following year, in the same way as for spring sowing. When cultivating and weeding, do not plow too deeply, so as not to damage the roots; when cultivating during the seedling stage, protect the seedlings well, prevent them from being pressed by clods of soil, and do not bruise the seedling stems; after the last cultivation, hill up soil to protect the roots.
Topdressing and watering: After each cultivation and weeding, apply topdressing once, with nitrogen fertilizer being best. Urea, ammonium sulfate, cake fertilizer, or human and livestock manure and urine can all be used. When topdressing, pay attention to watering, and never let the fertilizer be too concentrated, so as not to damage the seedlings. Especially when applying cake fertilizer, it is emphasized that it should be crushed, fully decomposed with water, diluted with water, and then applied. During the rainy season when rainfall is concentrated, prevent water accumulation and pay attention to timely drainage.
Pest and Disease Control
Diseases: Powdery mildew, rust, and sclerotinia are commonly seen.
(1) Powdery mildew occurs from Guyu to Lixia, and is prone to appear in late spring and early summer. It damages leaves and stems. The leaves turn yellow and lose green color, with white powdery material growing on them. In severe cases, it can cause the leaves to wither. It can be controlled by continuously spraying 2-4 times with a 1000-1200 times solution of 50% wettable thiophanate-methyl powder or 80 units of Qingfengmycin. Powdery mildew should be controlled early; at the initial stage of occurrence, control once, and during the peak period of disease, control continuously 2-3 times.
(2) Rust mostly occurs from Qingming to Mangzhong (April-May) and damages the leaves. After onset, reddish-brown protrusions appear on the underside of the leaves, and yellow spots appear on the upper surface, causing the entire leaf to curl, wither, and fall off. At the initial stage of onset, spray a 300-400 times solution of ferrous sulfate or 0.2-0.3 degree Baumé lime-sulfur mixture, and then spray continuously 2-3 more times at intervals of 7-10 days.
(3) Sclerotinia is a relatively serious disease harming motherwort. It can occur throughout the entire growth period. For spring sowing, the disease is serious from Guyu to Lixia; for autumn sowing, from Shuangjiang to Lidong. It is mostly caused by rainy weather and humid climate. After infection, white spots appear at the base, followed by rotting of the cortex. The diseased part has white silky mycelium. When seedlings are infected, the affected part rots and dies. If infection occurs during the stem-bolting stage, the epidermis peels off and the interior becomes fibrous until the plant dies.
Control methods: First, pay more attention when selecting land, persist in paddy-upland rotation, and preferably rotate with gramineous crops; second, when viral infection is found, promptly remove the diseased soil, spread quicklime powder, and at the same time spray a 600 times solution of 65% wettable zineb powder or a 1:1:300 Bordeaux mixture solution.
Insect pests: aphids, cutworms, and others.
(1) Aphids are relatively serious, harming plants and often causing them to shrink and die. Control methods: First, sow at the appropriate time to avoid the pest's growth period and reduce aphid damage. Second, after occurrence, spray to kill with a 1:1:10 solution of tobacco and lime water or a 2000 times solution of 40% dimethoate emulsifiable concentrate.
(2) Cutworms harm seedlings and easily cause missing plants and short stands. Control methods: methods such as trapping and killing with grass piles and capturing and killing in the morning can be adopted, and poison bait can also be used to kill them.
In addition, pests such as red spiders and white grubs also occur in motherwort fields, but they are not serious, and conventional methods can be used to control them. There is also animal damage, namely that during the seedling stage, wild rabbits often come to eat them. Lime can be spread in the field or scarecrows can be set up as barriers to frighten them away or they can be hunted and captured, to prevent the seedlings from being destroyed.