Detailed Explanation of Schizonepeta Planting Techniques and Field Management Methods

I. Plant Morphology

Annual herb, 80-100cm tall, with a strong aroma. Stem square, covered with short soft hairs, slightly purple at the base, upper part much branched. Flowering period 6-8 months; fruiting period July to September. Nutlets ovate or elliptical, surface smooth and brown. Cultivated in most parts of the country. Mainly produced in Hebei, Jiangsu, Zhejiang, Jiangxi, Hubei, Hunan.

II. Growth Habits

Schizonepeta has no strict requirements for climate, soil and other environmental conditions, and can be planted in both northern and southern parts of China. It prefers a warm, humid climate. Seedlings can tolerate low temperatures of around 0℃, and below -2℃ frost damage will occur. It dislikes drought and waterlogging, and dislikes continuous cropping. The suitable temperature for seed germination is 15-20℃. Seed lifespan is 1 year.

III. Cultivation Techniques

1. Site selection and land preparation: It is best to choose relatively fertile, moist, well-drained sandy loam soil for planting, and flat land with plenty of sunlight is preferable. Schizonepeta seeds are tiny, so land preparation must be meticulous while applying sufficient base fertilizer, about 35-40 kg of compound fertilizer per mu. Then plow to a depth of about 25 cm, crush the soil clods, repeatedly harrow finely, and level.

2. Propagation method: Propagated by seed, either direct sowing or seedling transplanting. Generally direct sowing in spring or summer.

Spring sowing in March-April, summer sowing in May-June; after the wheat harvest, immediately prepare the land and make beds, open shallow furrows 0.5 cm deep at a row spacing of 40 cm. When sowing, spread the seeds evenly in the furrows, cover with soil and level, and press down lightly. Use 1 kg of seeds per mu. Spring or autumn sowing is also possible, but autumn sowing occupies the land for a longer time, so it is generally seldom used. Broadcasting can also be used as a sowing method.

3. Field management

(1) Cultivation and weeding: Cultivation should be shallow to avoid pressing down the seedlings. For broadcast-sown plants, only weeding is needed. Depending on soil compaction and weed conditions, cultivation and weeding can be done 1-2 times.

(2) Topdressing: Schizonepeta requires relatively more nitrogen fertilizer, but in order to have strong stalks and many spikes, phosphorus and potassium fertilizers should be appropriately applied as topdressing. Generally, when the seedlings are 10 cm tall, apply 25-30 kg of urea per mu, and a small amount of phosphorus and potassium fertilizer can also be applied.

(3) Drainage and irrigation: During the seedling stage, water frequently to promote growth. After the plants mature, drought resistance increases, but waterlogging should be avoided, so if there is too much rain, excess water should be drained promptly.

4. Pest and disease control

(1) Root rot: Occurs easily under high temperature and waterlogging.

(2) Stem blight: Damages stems, leaves and flower spikes. Control methods: clean the field; rotate with gramineous crops; rake 200 kg of composted bacterial fertilizer per mu into the 3-4 cm soil layer.

(3) Pests: Include cutworms, silver-striped noctuid moths, etc.

(IV) Harvesting and Processing

For spring-sown plants, harvest in August-September of the same year; for summer-sown plants, harvest in October of the same year. When some seeds on the flower spikes turn brown and the flowers at the top have not yet all fallen, after the dew has dried on a sunny day, cut the whole plant from the base with a sickle and dry it in the sun; this is whole Schizonepeta; if only the flower spikes are harvested, they are called Schizonepeta spikes, and the stalks with the spikes removed are called Schizonepeta stalks. Whole Schizonepeta is best when green in color, with thick stems and long, dense spikes; Schizonepeta spikes are best when long, without stalks, with a rich aroma and no impurities. Generally, the yield of whole Schizonepeta is about 500 kg per mu.

(V) Before the autumn harvest, select individual plants in the field that are strong, with abundant branches, many and dense spikes, and free of pests and diseases as seed plants. The seed collection time must be 15-20 days later than the product harvest. When the seeds are fully mature, plump, and dark brown or brownish, harvest, dry and thresh, remove impurities, place in cloth bags, and hang in a ventilated, dry place for storage.