In Bangladesh, tea cultivation first started near the Chittagong Club in the 1840s. Malnicherra in Sylhet is the first tea garden of Bangladesh established in 1854 and in commercial production in 1857.
The main tea growing areas lie to the east of the Ganga-Jumma flood plain in the hill areas bordering Cachar tea growing area of India. Most of the tea grows in Sylhet in the North East in the so called Seven Valleys; tea is also grown in Chittagong & the Hill Tracts. Tea is grown at only 80-300 feet above sea level.
The seasonal nature of rainfall and temperature results in an uneven pattern of tea production. Annual rainfall is the range of 90-180 inches and it falls mainly between May and October when it is more than adequate, so that almost 80% of the crop is manufactured in the six months during June to November.
The dry season from mid-October to mid-May is divided into a Cool Season to mid-February and this is followed by a very hot desiccating season until mid-May which .causes severe stress in unshaded tea on southerly to westerly slopes.
Most estates are situated on valley sides but perhaps 25% of the area runs clown into swampy valley bottom in which tea can only be maintained if the land can be drained and kept free from water backing up from paddy cultivation downstream.
The topography rises from these; bheels, or low flats, through high flats or undulating – slopes representing perhaps 45% of the areas under tea to steep sloping hills or ridges called tillahs.
There are two major geological formations in Bangladesh, both sedimentary in origin. The older of the two forms the hills and consists of quartzite gravels, ferruginous gravels and sandstones, siltstones and clays with outcrops of laterite, ferrocrets and occasionally lignites. It has been affected by metamorphosis in places. The younger formation, still being deposited, forms the lowlands and consists of sands, silts and clays brought down by the river systems draining part of the Himalayas and the hills in Manipur and Mize districts. The older formation will give soils rich in iron tending to be acid whilst the younger formation, with poor inherent nutrient values, will provide soils with adequate calcium inherently fertile but liable to water logging in low-lying areas.