Lanxangia tsaoko (scientific name: Amomum Aromaticum Roxb) is a part of ginger family. There are two types of lanxangia tsaoko, which are red and green lanxangia tsaoko. In Viet Nam, lanxangia tsaoko has been discovered as a a valued product and cultivated by the ethnics in the Northern mountainous region such as Lào Cai, Lai Châu, Cao Bằng, Hà Giang, Tuyên Quang provinces since the late 18th century. Lanxangia tsaoko is widely used in culinary. Thanks to its aromatic, sweet and spicy characteristics and its health benefits, lanxangia tsaoko is considered the “queen of spices”.
In Hà Giang, highlanders of Vị Xuyên district has been cultivating lanxangia tsaoko under the forest foliage for about 30 years and it is regarded as the “golden plant” that they keep in the forest. In the recent 15 years, lanxangia tsaoko in the district has become an herb with high economic value. Therefore, lanxangia tsaoko has become the main product, bringing stable income and helping eradicating poverty for main ethnic households in the mountainous region.
Lanxangia tsaoko planting area
Vị Xuyên lanxangia tsaoko is planted in the communes of Cao Bồ, Phương Tiến, Thượng Sơn, Quảng Ngần, Lao Chải, Xín Chải, Thanh Đức, Thanh Thủy, Kim Linh of Vị Xuyên district, Hà Giang province. Lying alongside the Tây Côn Lĩnh range, this area has a complex topography on the granite mountains, upstream of Chảy river. The average altitude is over 1,300 metre, the terrain is highly divisive with the inclination of 40 - 45°. The annual average temperature of the area is under 16°C, average humidity is 81 - 86%, average rainfall is 1,744.6mm, drizzles happen 4.9 – 10.4 days per month in less rainy months.
Thanks to the low temperature, high rainfall (Vị Xuyên is among the areas with highest rainfall in Viet Nam), especially in May and June when lanxangia tsaoko flower bloom, the number of fruits of Vị Xuyên lanxangia tsaoko is lower than other areas’, but the fruits are bigger and juicier, the sizes are more consistent and have no underdeveloped seed. The soil for planting lanxangia tsaoko are humic acrisols on granite and mountainous humic acrisols. The soil is acidic to slightly acidic, the average pHKCl is 4.2. The surface layer organic matter content, phosphorus content and potassium content are respectively 52.52%, 48.07 mg/100g of soil and 50.32 mg/100g đất. Vị Xuyên lanxangia tsaoko is cultivated under the shade from forest foliage of trees with wide leaves. Therefore, the soil for Vị Xuyên lanxangia tsaoko has considerably thick O horizon of 20 - 40 cm, the higher the altitude, the thicker the O horizon. The O horizon is one of the decisive elements to the productivity and quality of lanxangia tsaoko.
Lanxangia tsaoko plant
Thanks to the geographical area’s characteristics, Vị Xuyên lanxangia tsaoko is big, juicy, thin skin with thick, firm flesh and no underdeveloped seed. The skin has a consistent light brown colour with visible veins and shiny inner texture. The lanxangia tsaoko has a natural aroma and pleasant sweet and spicy taste. The raw protein content is ≥ 5.67%. The essential oil content of Vị Xuyên lanxangia tsaoko is ≥ 1.99 %, higher than that of other areas’ lanxangia tsaoko. The total acidic content is ≥ 0.71%, ash content is ≥ 5.03 %. Vị Xuyên lanxangia tsaoko is dry with the humidity at ≤ 14.39 %.
For the lanxangia tsaoko to have such quality, in addition to the suitable natural conditions, the experience and tradition of the locals also contribute to the reputation of Vị Xuyên lanxangia tsaoko. In Vị Xuyên, the farmers have formulated their own rules and regulation on the conservation of the forest and protection for the lanxangia tsaoko gardens, with cross monitoring and inspection is conducted by producers. Thanks to that, lanxangia tsaoko is harvested in the right season with the assurance of ripeness and highest quality. At the same time, during the growth of the plant, the producers use no fertilizer and pesticide to ensure the quality and food safety of the product.