Hanzhong Winter Leeks

Hanzhong Winter Leeks

Hanzhong winter leeks are a geographical indication agricultural product.

　　Hanzhong winter leeks have a long cultivation history. Originally grown around Guojielou Village by the Han River in Hanzhong City, southern Shaanxi, they have been carefully selected through natural processes and nurtured by local farmers. Nowadays, Hanzhong winter leeks are widely cultivated across various counties and cities in the Hanzhong region. These winter leeks are highly nutritious—their carotene content is second only to carrots, more than double that of scallions, and 27 times higher than that of celery. They also contain aromatic volatile essential oils and sulfur compounds, which contribute to their distinctive flavor and antibacterial properties. Thanks to their pungent and fragrant taste, they can be used as a seasoning—whether stir-fried, boiled, served cold, in soups, or as stuffing, even in small amounts, they add a delicious aroma. Leeks are also considered a medicinal herb. Their leaves and roots are believed to invigorate, disperse blood stasis, promote blood circulation, stop bleeding, relieve diarrhea, tonify the spleen, support liver function, and improve circulation. They are beneficial in treating injuries, choking sensations, acid reflux, enteritis, vomiting blood, and chest pain. Leek seeds act as a stimulant, helping to consolidate essence, support yang energy, nourish kidneys, treat leukorrhea, and warm the waist and knees. Hence, traditional Chinese medicine refers to leeks as the “yang-invigorating herb.”

　　Geographic Scope

　　Hanzhong City in Shaanxi Province, historically known as “Tianhan,” is located in the southwestern part of the province. It borders the Qinling Mountains to the north and the Daba Mountains to the south. To the west, it connects with Gansu, and to the south with Sichuan. Its eastern and northern parts border Ankang Prefecture and the cities of Xi’an, Xianyang, and Baoji within the province. Geographic coordinates: longitude 105°30′50″–108°16′45″, latitude 32°08′54″–33°53′16″. The five plains counties and one district have an average elevation of about 500±10 meters, covering a total municipal area of 27,107.5 square kilometers.

　　Hanzhong winter leeks are a traditional variety of household-grown leeks in Hanzhong City, Shaanxi Province. They are planted across five counties and one district in the Hanzhong Basin, including: 31 towns and subdistricts in Nanzheng County (Dahedang Town, Liangshan Town, Chengguan Town), Chenggu County (Bowang Town, Sanhe Town, Liulin Town, Wenchuan Town, Cuijiashan Town), Yang County (Guanci Town, Yangzhou Town, Yishui Town, Xiecun Town, Machang Town), Mian County (Mianyang Town, Wuhou Town, Dingjun Town, Changlin Town, Huangsha Town, Jinquan Town, Yuandun Town, Laodaosi Town), Xixiang County (Chengguan Town, Geshi Township, Yankou Town), and Hantai District (Longjiang Town, Qili Town, Pu Town, Zongying Town, Shujiaying, Beiguan Subdistrict Office, Hanzhonglu Subdistrict Office). Over 2,600 acres of Hanzhong winter leeks are planted annually here, with a total annual yield of 6,500 tons.

　　Natural Ecological Environment and Human Historical Factors

　　(1) Soil and Topography: The Hanzhong Basin developed from a rift valley between the Qinling and Daba Mountains. Centered on the Hanzhong Basin and extending toward the main ridges of these mountain ranges are plains, hills, low mountains, and mid-to-high mountains, showing a distinct zonal topographic feature. Along the Han River are alluvial plains formed by river sedimentation, characterized by sandy loam soil. After centuries of farming by local growers, the soil has been improved to resemble loamy soil. The soil is neutral to slightly acidic, with a pH value of around 6.5.

　　(2) Hydrology: Hanzhong City has two major rivers, the Han River and the Jialing River. Surface runoff is abundant, with 528 tributaries between the two rivers. The Han River basin covers 72.2% of the city’s total area, with 340 tributaries, while the Jialing River basin accounts for 27.8%, with 188 tributaries. The city’s total annual runoff is 14.41 billion cubic meters, 69.3% of which comes from the Han River basin. The Jialing River has an average sediment concentration of 8.6 kg/m³. The upper reaches of the Han River, due to sparse vegetation and frequent human activity, have an average annual sediment concentration of 2.36 kg/m³, while other river sections have concentrations below 1.0 kg/m³.

　　The natural water quality in Hanzhong is generally good, suitable for human and livestock consumption, aquaculture, agriculture, and industrial use. Most waters are bicarbonate or carbonate types. The Han River water has a pH of 6.5–6.8, classifying it as weakly acidic, with a total hardness of 68–81 mg/L, considered soft water. The Jialing River has a pH of 6.2–6.7, also weakly acidic, with a total hardness of 83–91 mg/L, categorized as slightly hard water.

　　Hanzhong’s groundwater is generally abundant but unevenly distributed due to terrain, aquifer types, and precipitation patterns, resulting in notable regional differences. Generally, the southern region has better water availability than the north, and the basin area better than the hilly and mountainous areas. Two main groundwater distribution zones exist: the Han River plain zone and the red clay high terraces and low hills zone. The Han River plain zone includes the river floodplains and first- and second-level terraces of the Han River and its tributaries. The rock layers mainly consist of Holocene alluvial gravel and sandy loam, with aquifer thickness of 20–50 meters. The depth of shallow groundwater ranges from about 1 meter on the floodplain to 2–3 meters on the first terrace and 3–6 meters on the second terrace. The red clay high terraces and low hills zone include the third- and fourth-level terraces of the Han River and adjacent low hills. The aquifer layers are Quaternary lacustrine deposits of sandy loam, silty clay, and clay, with an aquifer thickness of about 5–40 meters and a shallow groundwater depth of 6–32 meters.

　　(3) Climate: Hanzhong enjoys favorable climatic conditions. The towering Qinling Mountains block the cold Siberian air masses from advancing southward, while the winding Daba Mountains draw warm, moist air currents from the Indian Ocean through gorges northward, creating a subtropical climate. The area experiences mild temperatures and abundant rainfall. The annual average temperature in the plains is 14.3°C, with annual sunshine hours ranging from 1,600 to 1,800. The average relative humidity in the five plains counties and one district is 77–80%, with lower levels in winter and spring, and higher in summer and autumn. Humidity peaks in September and October at 80–86%, and remains between 75–80% in winter. Annual precipitation is 871.8 mm, the frost-free period lasts 254 days, and the accumulated temperature above 10°C is 4,480°C. With no severe winters or scorching summers, ample water resources, lush bamboo and forests, and fragrant blooms and birdsong, it has long been known as the “Little Jiangnan of the Northwest” and the “Golden Jade Basin.”

　　(4) Human Historical Background: Hanzhong winter leeks have a long cultivation history. What began as a traditional household variety in Hanzhong has evolved into a renowned regional variety in Shaanxi, and was even included in the China Vegetable Varieties Registry as an important national high-quality leek resource. The discovery of Hanzhong winter leeks was quite accidental. In 1956, vegetable expert Researcher Ren Shengjian from Shaanxi Province, while surveying premium vegetable varieties across the province, discovered an outstanding household leek variety in Guojielou Village, Hanshui Township, Hanzhong City. Locals called it “winter leek” (as there was another type referred to as simply “leek”). No one knows exactly how many dynasties it had been cultivated or when it originated, but locals observed that it was more cold-resistant, heat-tolerant, high-yielding, and of superior quality compared to ordinary leeks, so it was passed down through generations. Researcher Ren identified this variety as possessing many valuable agronomic traits—its exceptional productivity, high quality, especially remarkable cold and heat resistance, were unmatched by other leeks. He introduced it to the Shaanxi Vegetable Research Institute, naming it “Hanzhong Winter Leek.” After trial planting and observation in Wugong and Xi’an, it performed excellently and ranked among the best in the provincial leek germplasm resource garden. Thus, this age-old household variety became officially recognized as a high-quality Shaanxi variety under the name “Hanzhong Winter Leek.” In the 1950s, chive sprouts produced from Hanzhong winter leeks were once airlifted to Beijing for state banquets to entertain foreign guests, greatly boosting its fame. In the 1960s, it was introduced to Shandong, and in the 1970s to Tianjin. Trial plantings in both regions yielded excellent results. In 1982, the Shaanxi Provincial Crop Variety Approval Committee designated Hanzhong Winter Leek as one of the first batch of premium local vegetable varieties. It was recognized by the Shandong Provincial Crop Variety Approval Committee in 1986 and the Tianjin Municipal Crop Variety Approval Committee in 1987. This once obscure household leek variety quickly rose to become a nationally renowned rare breed. In 1991, it was included in the book China’s Famous, Special, and High-Quality Vegetables and Their Cultivation (Shanghai Science and Technology Press) and selected for inclusion in the textbook Chinese Vegetable Cultivation (Northern Edition).

　　Production Technical Requirements

　　(1) Origin Selection: The origin for Hanzhong winter leeks must comply with the pollution-free vegetable production environment standards NY/T 5010-2002.

　　(2) Variety Selection and Specific Requirements: Seeds exhibiting typical characteristics of Hanzhong winter leeks must be selected for cultivation.

　　(3) Production Process Management: The production process of Hanzhong winter leeks must adhere to the pollution-free leek production technical regulations NY/T 5002-2001.

　　(4) Product Harvesting and Post-Harvest Handling: Hanzhong winter leeks are available year-round. The earliest harvest of greenhouse green leeks in Hanzhong begins in mid-February. After harvesting, the leeks are preliminarily sorted to remove mud and impurities, bundled into one-kilogram bunches, packed in bamboo baskets or cardboard boxes, and brought to market.

　　(5) Production Record Requirements:

　　① Detailed records of the dates of agricultural operations;

　　② Accurate records of harvest dates, product types, and quantities (product types refer to green leeks, yellow leeks, leek scapes, seeds, etc.);

　　③ Agricultural input records: a) types, quantities, usage times, and frequency of fertilizers;

　　b) types, concentrations, application dates, and frequency of pesticides;

　　④ Accurate records of the planting duration of leeks in each plot.

　　Typical Quality Characteristics and Product Quality Safety Standards

　　(1) Botanical Features: Hanzhong winter leeks have been physiologically identified by the Institute of Vegetables and Flowers at the Chinese Academy of Agricultural Sciences as tetraploid crops—a key inherent advantage that distinguishes them from other leek varieties, which are diploid.

　　Typical quality characteristics of the product and regulations on product quality and safety

　　(1) Botanical characteristics: Hanzhong winter Chinese chives have been physiologically identified by the Institute of Vegetables and Flowers at the Chinese Academy of Agricultural Sciences as a tetraploid crop, which is the inherent advantage of Hanzhong winter Chinese chives over other varieties of Chinese chives (all of which are diploid crops).

　　The winter leek of Hanzhong has taller plants than ordinary leeks, reaching a height of 40–50 centimeters; the leaf cluster is semi-erect, with each plant maintaining 5–7 leaves; the leaves are flat, slightly three-edged, thick and fleshy, broad in shape, measuring 32–42 centimeters in length and generally 0.8–1.1 centimeters in width, with the widest reaching 1.7–1.9 centimeters. They are light green in color, with bluntly rounded tips, and the leaf sheaths are 0.5–0.7 centimeters thick, yellowish-white, with nearly circular cross-sections.

　　(2) Intrinsic Quality: Hanzhong winter leek is a premium vegetable among greens, known for its wide, tender leaves, vibrant color, authentic flavor, strong spiciness, minimal fiber content, rich nutrition, excellent quality, and good market appeal. It is also very high in carotene content, with 3.26 mg of carotene per 100 g of fresh leek, second only to carrots, more than double that of scallions (1.48 mg), and 27 times higher than that of celery (0.11 mg). Additionally, leeks contain aromatic volatile essential oils and allyl sulfide, which contribute to their distinctive fragrance and antibacterial properties. Consuming them can stimulate saliva production, enhance appetite, aid digestion, promote blood circulation, boost energy, nourish the stomach, and darken hair.

　　(3) Safety Requirements: The quality and safety standards of Hanzhong winter leek must comply with the NY/5001-2001 standard for pollution-free leeks.

　　Packaging, labeling, and related regulations

　　Packaging must clearly indicate the words “Pollution-Free Food – Hanzhong Winter Leek.” Each package should display where the product is from, the product’s standard code, trademark, name of the producing entity, detailed address, specifications, net weight, harvest date, and packaging date. The text on the label should be clear, complete, and accurate.