The coffee trees can stand cold—if not of long duration—down to freezing-point, as well as a fairly high temperature. Unlike the Liberia coffee, they fare better on undulating or broken ground than on the flat.
Two distinct seasons—the dry and the rainy—each of about six months' duration—such as are found in the above-mentioned States of Brazil, seem perfectly to suit the growth of the coffee trees. The trees are in bloom for three or four days some time during the months of September to December. If the rains are not abundant when the trees are in blossom, and during the maturing of the fruits, the latter do not develop properly, especially those at the end of the branches, where the berries become dry before their time or even do not form. If the rain comes too long before the trees are in bloom it causes the blossoms to open before their time and they are frequently spoiled by the cold which follows. The coffee beans are collected in April, during the dry weather.
The coffee trees are very sensitive to winds, cold or hot, especially when blowing continuously in the same direction, which causes the undue fall of leaves and rupture of the bark at the neck of the roots. Wind, indeed, is one of the most dangerous enemies of coffee trees, and it is to obviate this danger that in many countries—but not in Brazil—a protecting plantation in lines of other trees—generally useful fruit trees—is adopted in order to screen the coffee trees from the prevailing wind, as well as to give a further income from the fruit produced.
It has been proved that even from good trees below a certain altitude the coffee is of inferior quality, while above that height the crop becomes irregular. In zones fully exposed to the sun the quality is superior to that of regions where the sun does not reach or only reaches for a short portion of the day.
The Coffea Arabica is not particularly exacting in the quality of the soil, but the soil on which it flourishes best is that formed in great part by decomposed vegetable matter—as, for instance, from ancient trees mixed with volcanic earth, such as the famous red earth of the State of São Paulo. Volcanic cinders also are said to be wonderful fertilizers for the soil, and well adapted for the welfare of coffee trees.
One thing is undoubted, and that is that the State of São Paulo possesses the ideal soil for coffee plantations. Analysis has shown that, curiously enough, the soil of São Paulo is not in itself very rich. It has an insufficient quantity of fertilizing substances, particularly of lime; but it should not be forgotten that locality and climatic conditions must be taken into serious consideration, and that we must not be misled by the difference between the apparent and the real fertility of the soil. What would be a poor soil in Europe may prove to be an excellent one in a tropical country. So the famous "red earth" of São Paulo, which in a drier climate would be sterile and unproductive, is there excellent because of its extremely permeable, porous and powdery qualities.
The special terms used for naming the different kinds of earth suitable for the cultivation of coffee are: terra roxa (red earth), massapé, salmorão, catanduva, terra de areia (sand earth), picarra (stony earth), and pedreguelho (stony earth).
The terra roxa is an argillaceous, ferruginous earth of diabasic origin, occasionally mixed with sand. It contains salicylic acid, oxide of iron, alumina, phosphoric acid, oxide of manganese, lime, magnesia, potash and soda.
The massapé, originally decomposed gneiss-granitic rock mixed with clay, contains oxide of iron. Its occasional blackness is due to the decomposed vegetable matter it embodies.