In fixing on any district to plant Tea in, four things have to be considered--viz., soil, climate, labour, and means of transport. When--the district being selected--a site has to be chosen, all but the second of these have to be considered again, and the lay of land, nature of jungle, water, and sanitation are also of great importance in choosing a site.
I will first, then, discuss generally the Tea districts given above as regards the advantages of each for Tea cultivation. I have seen and studied Tea gardens in all the districts named, except No. 2. What I know of the Dehra Dhoon is from what I have read, and what is generally known of the climate.
Before, however, comparing each district, we should know what are the necessities of the Tea plant as regards climate and soil. Tea, especially the China variety, will grow in very varying climates and soils, but it will not flourish in all of them, and if it does not flourish, and flourish well, it will certainly not pay.
The climate required for Tea is a hot damp one. As a rule, a good Tea climate is not a healthy one. The rainfall should not be less than 80 to 100 inches per annum, and the more of this that falls in the early part of the year the better. Any climate which, though possessing an abundant rainfall, suffers from drought in the early part of the year is not, _cæteris paribus_, so good as one where the rain is more equally diffused. _All_ the Tea districts would yield better with more rain in February, March, and April; and therefore some, where fogs prevail in the mornings at the early part of the year, are so far benefited.
As any drought is prejudicial to Tea, it stands to reason hot winds must be very bad. These winds argue great aridity, and the Tea plant luxuriates in continual moisture.
The less cold weather experienced where Tea is, the better for the plant. It can stand, and will grow in, great cold (freezing point, and lower in winter, is found in some places where Tea is), but I do not think it will ever be grown to a profit on such sites. That Tea requires a temperate climate was long believed and acted upon by many to their loss. The climate _cannot_ be too hot for Tea if the heat is accompanied with moisture.