Altitude. Coffee is found growing in all altitudes, from sea-level up to the frost-line, which is about 6,000 feet in the tropics. Robusta and liberica varieties of coffee do best in regions from sea-level up to 3,000 feet, while arabica flourishes better at the higher levels.
Carvalho says that the coffee plant needs sun, but that a few hours daily exposure is sufficient. Hilly ground has the advantage of offering the choice of a suitable exposure, as the sun shines on it for only a part of the day. Whether it is the early morning or the afternoon sun that enables the plant to attain its optimum conditions is a question of locality.
Cross Section of Mountain Slope in Yemen, Arabia, Showing Coffee Terraces
These miniature plantations are found chiefly along the caravan route between Hodeida and Sanaa
Clearing Virgin Forest for a Coffee Estate in Mexico
