The British planted Tea not only in Assam but also in other regions as well across Himalaya and Western Ghats. Why sugar plantations seceded in limited areas. Discuss?

Model Answer: Tea plantations succeeded in only regions of monsoon belt viz. Assam, West Bengal and the foot hills of the Himalayas in the North and the moist slopes and the plateaus of the Western Ghats in the south.
Not much success was received in other areas such as Himachal Pradesh, Ranchi, Doon valley etc.  There were various geographical as well as other reasons of why the tea plantation was not successful in these areas.  The Ranchi gardens have poor soil not suitable for tea cultivation.  The rainfall, temperature and humidity needed by tea were not available in Himahchal Pradesh and Dehradun although soil in Dehradun is equivalent to that of Assam. Tea needs relatively low temperature for its growth, but not very low, that can adversely affect cultivation of tea.
For example, the Kangra valley lies in the foot hills of Himalayas and here climate is too cold.  Additionally, tea requires high rainfall of around 150-250 cm along with well drained slopes.
The combination of all these factors exists in the areas of North East, Assam and areas near Darjeeling; as well as in Nilgiri hill.