How to cultivate and manage fennel? A full breakdown of the key points
Fennel greens, also originally called small fennel, are also known as fragrant silk vegetable, small fennel, fennel seed, grain fragrance (Sichuan, Guizhou), and hun xiang; the tender leaves are used as a vegetable, and it is the stem part of small fennel, the dried mature fruit of the Umbelliferae plant fennel. It was first recorded in the Tang Materia Medica. Su Song said that northerners call it fennel, and the sound is close to huai xiang. Tao Hongjing said: when boiling spoiled meat, add a little, and there is no bad smell; spoiled sauce also becomes fragrant when the powder is added, hence it is called fennel. Li Shizhen said that common people often chew it while carrying it in their bosoms, so perhaps the name huai xiang comes from this. The fruit (small fennel) is used as a spice and also for medicinal purposes; the roots, leaves, and whole plant can all be used as medicine.
Small fennel is the same plant, and when compared by botanical traits such as leaf color, leaf shape, inflorescence, fruit, and seeds, as well as other characteristics such as quality and flavor, it is extremely similar; the only difference is that fennel's leaf sheaths wrap around each other to form a flattened spherical or round bulb. When mature, this becomes the main edible part, while the fine leaves and petioles are usually eaten only when the plant is relatively tender. The thick, plump leaf sheath part of fennel is fresh, tender, and crisp; it is generally cut into fine strips and eaten raw as a cold dish with seasonings, or stir-fried with various meats.
Morphological characteristics of small fennel
Small fennel belongs to the Umbelliferae family and is an annual herbaceous crop. The stem is upright, cylindrical, and smooth; the leaves are pinnate and multi-divided, with compound leaves deeply cleft like threads; the petiole is light green; the flowers are yellow in compound umbels, with no involucre or involucel bracts; the fruit (seed) is linear-oblong, smooth, and single; the plant grows 30-35 cm tall, and the growth period is about 90 days. After the fruit matures, it is orange-yellow, bright in color, and aromatic, with a 1000-grain weight of 2-2.3 grams.
Environmental requirements of small fennel
Small fennel prefers a cool climate and is relatively tolerant of drought, but not of moisture. Because the small fennel plant is short and its root system is relatively shallow, generally distributed 5-10 cm in the soil layer, it has strict soil requirements and is most suitable for planting in sandy loam soil with an organic matter content of 1.5%-1.8%.
The most suitable temperature for the growing period of small fennel is 15-20°C. Above 25°C, growth is slow; below 5°C, growth is inhibited. When sowing, if the soil temperature is 5-10°C, seedlings emerge in 15-16 days; at 12-15°C, they emerge in 7-8 days. From sowing to maturity is 85-95 days, and from flowering to maturity is 25-30 days.
Key points of cultivation and management of small fennel
1. Land selection
Small fennel seeds are small, with about 500,000 seeds per kilogram, and are not easy to emerge, so land selection and land preparation are very strict. Choose sandy loam soil with medium to high fertility and an organic matter content of 1.5%-1.8% or more. Never plant it on saline-alkali soil or heavy clay plots. Plots with wheat, oats, or many weeds as the previous crop are not suitable for planting.
2. Land preparation standard
Small fennel seeds are small and have poor soil-breaking ability. During land preparation, the six-character standard of fine, loose, clean, level, crumbly, and moist must be met. During land preparation, plowing, harrowing, and cultivating should be combined in one continuous compound operation, achieving no small pits, no clods larger than 3 cm, no residual film, weeds, or stems, and loose soil, level ground, and sufficient moisture.
Choose suitable land, apply 45,000 kg of high-quality barnyard manure per hectare, deep plow more than 30 cm, harrow level and fine, and make flat beds 80 cm wide. When the soil is dry, first release water into the beds, and sow when the water has infiltrated and the surface soil is slightly loose.
2. Propagation method: sow between the "Spring Equinox" and "Pure Brightness." Before sowing, select plump new seeds, soak them in 40°C warm water for 1-2 hours, remove them, wrap them in a gauze bag, place them in a warm place, rinse them with warm water twice a day, and sow once the seeds have slightly begun to sprout. Open furrows 3-5 cm deep in the beds at a row spacing of 40 cm, evenly scatter the seeds in, cover with soil, level, and press lightly. After sowing, seedlings generally emerge in 10-15 days. The seeding rate per hectare is 22.5-30 kg. Raising seedlings and transplanting gives higher yields.
3. Sowing period and seeding rate
Small fennel should be sown early rather than late, generally finished in mid-March, and at the latest in early April. The seeding rate is 1-1.5 kg per 667 square meters, sowing depth is 2.5-3 cm, and 10-15 kg of compound phosphate fertilizer is applied per 667 square meters.
4. Sowing method
Small fennel is mostly sown in drills or broadcast. For drilling, use equal row spacing of 20 cm or wide-narrow rows of 15×30 cm. It can also be sown by opening furrows and building ridges, or in small beds. After sowing, press to preserve soil moisture and promote strong, uniform seedlings.
In recent years, intercropping and relay cropping with cotton, corn, vegetables, and other crops has often been used to make full use of light and heat resources, increase the multiple cropping index, and increase economic income.
Field management of small fennel
When the seedlings show rows, cultivate and loosen the soil in time, preserve moisture, and pull out weeds between plants. If rain occurs, harrow the ground crosswise in time to benefit seedling growth. Because there are many kinds of weeds in small fennel fields and they grow quickly, they must be completely removed before the rows close. If dodder harms the crop in the middle and late stages, use 40% dilaan emulsifiable concentrate at 200-300 times dilution and spray after 5 p.m. for control, and remove by hand if necessary.
Small fennel has a short growth period and small growth amount, and needs little fertilizer and water. Generally, sufficient base fertilizer and seed fertilizer are applied before sowing, and no irrigation or fertilization is needed. If the soil is poor, before row closure (3-4 true leaves), apply 8-10 kg of urea per 667 square meters together with the first irrigation, using water to regulate fertilizer and fertilizer to promote seedlings. In the early flowering stage and grain-filling stage, spray 200-250 grams of potassium dihydrogen phosphate per 667 square meters to promote more fruit set, more seed set, and increase grain weight. Irrigate the second time in the late flowering stage and early grain-filling stage, and irrigate the third time at the end of grain filling to promote early maturity. Irrigation should be done in the morning and evening, timely and in appropriate amounts, avoiding irrigation during high temperatures to reduce seedling death. Insisting on irrigating according to the seedlings, soil, and weather is the key to a high yield of small fennel.
After emergence, water appropriately according to drought conditions to keep the bed surface moist during the seedling stage. Combined with cultivation and weeding, when the seedlings are 6-8 cm tall, thin them to a plant spacing of 9 cm; when the seedlings are more than 15 cm tall, final thinning is done at a plant spacing of 20 cm. When the seedlings are 30 cm tall, apply topdressing, mainly with quick-acting organic fertilizer, and increase the application of superphosphate. Water in dry weather, and drain water in time during the rainy season to prevent root rot. In the Jinnan area, after harvest in the same year, covering the roots with a layer of cow or horse manure or mixed soil manure can allow safe overwintering; the next year they sprout early, grow vigorously, and have a relatively high yield.
Harvest in time
When the small fennel seeds turn yellow and the stems and leaves appear wilted and withered, they can be harvested. Small fennel easily sheds grains and breaks branches, so harvesting should be done in the morning or evening.