How to Grow Mint? Mastering These Cultivation Techniques Is Key

Mint, also known as Rendan grass, is a perennial herbaceous plant of the genus Mentha in the Lamiaceae family, distributed in various regions. It has functions such as dispelling wind-heat, clearing the head and eyes, and promoting eruption. Its tender stems and leaves can be eaten as a cold dish, clearing heat and detoxifying, with a cool and refreshing taste. It is a leafy green vegetable with good development prospects that serves both as medicine and food.

I. Botanical Characteristics

The plant height is 30--80cm, and the whole plant has a cool fragrance. The rhizome is creeping and white. The aboveground stem is creeping or erect, green or purple, square, hollow, with recurved pubescence and glandular dots. The leaves are opposite, ovate or oblong-elliptical, with fine serrations on the edges, and sparsely pubescent and yellow glandular dots on both surfaces. The verticillaster is axillary, and the corolla is light reddish-purple, bilabiate. There are 4 nutlets, ovoid. The flowering period is August--October, and the fruiting period is September--November.

II. Ecological Habits

Mint is a shallow-rooted plant. Most of the rhizomes are concentrated within about 15cm of the soil surface, with a horizontal distribution of about 30cm. Both the rhizomes and aboveground stems have strong sprouting ability and are used as asexual propagation material in production. Mint has strong adaptability to environmental conditions and can grow in areas below 2100m in altitude. It is relatively shade-tolerant and can be intercropped with other crops, growing vigorously with excellent quality, but it prefers a sunny, warm and humid environment. The rhizomes sprout and emerge at 5--6℃, the suitable temperature for plant growth is 20--30℃, and the underground rhizomes can still overwinter safely at -30-- -20℃.

III. Cultivation Points

1. Site selection and land preparation: Choose sunny, flat, fertile sandy loam with convenient drainage and irrigation for planting. Apply 4000kg of farmyard manure per mu, together with 60kg of compound fertilizer as base fertilizer. Plow, refine, and harrow level to make beds 1--1.2m wide.

2. Propagation methods: In production, rhizome propagation is mainly used, and seedling propagation can also be used. Mint is mostly cultivated in open fields. In northern regions, protected cultivation can be used, or a combination of open-field and protected cultivation. The cultivation season depends on the climate of each region, and generally it can be cultivated in frost-free seasons. Protected cultivation can produce year-round; in northern regions, open-field cultivation can be done from April to October. Rhizome propagation: From late October to early November, dig up rhizomes from the seed reservation field, select white, thick, and short-internode ones, cut them into 10cm small sections, and immediately plant them into pre-dug 10cm deep furrows, with row spacing of 25--30cm and plant spacing of 15cm. After planting, cover with fine soil, harrow level, and compact. Seedling propagation: Select a field with robust plants, uniform growth, and no pests or diseases as the seed reservation field. After harvesting in autumn, immediately carry out intertillage, weeding, and topdressing once. In early April of the following year, when the seedlings are 15cm high, pull the seedlings and transplant them. Dig holes in the transplanting field according to row spacing of 20cm and plant spacing of 15cm, and plant 2 seedlings per hole. After planting, cover with soil and compact, then water with thin manure water.

3. Field management: After emergence, keep the field moist and free of weeds, water frequently with a small amount of water, and drain promptly if there is standing water. In order to prevent branches and leaves from shading each other, promptly guide the growth direction of aboveground stems and underground stems so that they do not become crowded. When the seedlings are about 15cm high and after each harvest, topdress promptly to promote the emergence of new branch tips. Generally, apply 1500kg per mu of diluted human manure and urine or urea solution. After each fertilization, water promptly.

4. Pest and disease control: Rust disease: Damages leaves and stems, and occurs frequently in rainy seasons. In addition to strengthening field management and improving ventilation and light transmission conditions, 25% triadimefon 1000--1500 times solution can be sprayed on leaves. Leaf spot disease (also known as white star disease): Damages the leaves, occurring from May to October. In the early stage of the disease, promptly remove and burn affected parts or spray with 75% chlorothalonil 500--700 times solution. The main insect pests are small cutworms and silver Y moths. For small cutworms, 40% fenpropathrin-malathion emulsifiable concentrate or fenpropathrin-killing emulsifiable concentrate 2000--3000 times solution can be sprayed at the root zone, or 40% isofenphos-methyl 1000 times solution can be used for root irrigation. For silver Y moths, 50% chlorfluazuron emulsifiable concentrate can be sprayed with 30--60ml per mu diluted in water, or 50% fenitrothion 1000 times solution can be sprayed for control.

IV. Harvesting: In areas with suitable conditions, planting once can allow continuous harvesting for 2--3 years. Generally, when the main stem is about 20cm high, harvesting of tender stems and leaves for consumption can begin. In southern regions, picking can be done all year round, with the highest yield and best quality from April to August when the climate is suitable, and the harvest interval is 15--20 days; in northern regions, protected facility cultivation in winter can also achieve year-round supply. For medicinal use, it is often harvested twice during the growing period. The first time (first cutting) is 5--6 days before Minor Heat, when the leaves are flourishing and the flowers have not yet opened, cutting the aboveground parts; the second time is between Autumn Equinox and Cold Dew, when the flowers are in full bloom and the leaves have not yet fallen. For medicinal use, the second harvest is better.

V. Seed reservation techniques: Mint is prone to degeneration, so seed reservation and selection work should be done well. Common methods include: 1. Plot selection for seed reservation. For fields with only a small amount of mixed and degenerated plants, in late April when the seedlings are 15cm high, or in late August when the second-cut mint is 15cm high, combined with weeding, remove wild species or other mixed species twice with roots, and at the same time remove inferior and diseased seedlings for seed reservation. 2. Repeat stubble seed reservation. In late April, select robust and non-degenerated plants in the field, transplant them to the seed reservation field at a spacing of 15cm x 20cm, strengthen management, cultivate until early winter and then dig them up, obtaining 70%--80% white new rhizomes for seed use.