Nepali tea teas like green tea, oolong tea, white tea and hand rolled tea fall under the category of orthodox tea. In Nepal, orthodox tea is produced and processed in the mountainous regions of Nepal at an altitude ranging from 3,000 – 7,000 feet above the sea level. There are six major districts, primarily in the eastern regions of Nepal that are known for producing quality orthodox tea, which are Ilam, Panchthar, Dhankuta, Terhathum, Sindhulpalchok and Kaski. Orthodox tea in Nepal is characterized by four flushes:- Crush, tear, curl (CTC) tea is a method of processing Assam variety "(Camellia sinensis" var. "assamica)",
Camellia sinensis pairs which was larger than most plants previously sequenced. "Camellia sinensis" is mainly cultivated in tropical and subtropical climates, in areas with at least 127 cm (50 inches) of rainfall a year. Tea plants prefer a rich and moist growing location in full to part sun, and can be grown in hardiness zones 7 – 9. However, the clonal one is commercially cultivated from the equator to as far north as Cornwall and Scotland on the UK mainland. Many high quality teas are grown at high elevations, up to , as the plants grow more slowly and acquire more flavour.