Cashew trees have a delicate root system. Because of this, seeds for commercial farms are sown in the fields rather than germinating elsewhere and then transplanted. They are planted during the rainy season because the moisture helps them sprout. If the weather is dry, store the seeds for short time, but they must be planted as soon as possible. They cannot germinate after being stored more than a few months. The seeds sprout and the cashew trees begin growing in about two weeks, although some seeds can take as long as two months to germinate.
Cashew trees flower as the first step in producing cashew nuts. These flowers are clusters of hundreds of tiny blossoms. A single tree may take two to three months to finish blooming. During this time, fruit forms where the flowers died. The first thing that grows is the cashew apple, which is edible. However, it must be left on the tree for the nut to develop. The apple continues growing and eventually produces a cashew nut in a hard shell at the end of the apple.
The cashew nut is encased in an outer shell that contains a dark, oily liquid that is sometimes used in varnishes and in plastic compounds. The liquid is caustic. Anyone handling cashew nuts before they are separated from their outer shells must use caution to avoid skin problems. Once the covering and the liquid are removed, the nut can be safely handled.
Once the cashew apple has formed and it has the nut on the end, it can be picked. However, the cashew nut is ripe if harvested that way. Only the cashew apple is ripe while still on the tree. Wait until the apple falls from the tree, and then pick the nut from the fallen fruit. The entire process from first flowering until the cashews are ready for harvest takes about two-and-a-half or three months.