Cocoa – or cacao – trees produce drupes that contain the cocoa beans from which chocolate is produced. Cocoa trees are extremely selective about where they grow, including the type of soil they prefer. They cannot handle too much sun or wind, or much variation in temperature. For this reason, they are tropical trees and only thrive within 20 degrees to the north or south of the Equator. When exposed to unfavorable conditions, the tree becomes stressed making it susceptible to attacks from pests and disease, and this can reduce production and even kill the tree.
Cocoa trees need soils with a neutral to very slightly acid pH balance. If your soil's pH is off, mix in a mixture of good compost and native topsoil to amend it. Amend no less than the top four inches of dirt in your selected planting site. Native to rain-forests in tropical regions, they are accustomed to a very rich growing medium with plenty of moisture.
While the trees are more adapted to a rich loam growing soil, they can also be cultivated in sandy soils. Dig a hole that is larger than the root ball of the tree your are planting to ensure that the sandy soil is well-loosened. The cocoa tree sends out a single tap root grows very deep, and needs to be able to penetrate the soil. The rest of the tree's roots are lateral and shallow. Water well upon planting, and be sure to remove air pockets when back filling.
If your planting site is host to hard, rocky soil, it is necessary to excavate a hole that is up to three times the depth of your tree's root ball or the container it comes in. It may be necessary to use an auger or excavating equipment to adequately dig the hole. Planting guidelines are the same as for sandy soil, but it is important to break up the rock so the tree's tap root has easy access as it grows.
Since cocoa trees prefer moist but well drained soil, if you are planting in an area that is sunken or close to the water table, create a mound of soil that is about three feet above ground level. It should also be no less than 4 feet in diameter, and can be as much as 10 feet wide. Dig your hole and place your tree as per the instructions for the soil type.