Plant the cassava in a sandy, well-drained garden soil when there's no danger of frosts or freezes. It appreciates lots of sunshine---at least six hours of direct sun daily. In hot or arid conditions, midday shade in the heat of the summer is recommended, according to Floridata. Cassava plants need at least eight months of frost-free growing before its tuberous roots become large enough to warrant harvest.
Irrigate the sand-based garden soil to keep the soil evenly moist, but never soggy. Supplement natural rainfall as needed to provide one to three inches of water weekly from spring to fall to keep the plant from prematurely wilting in the heat. Cassava plants are extremely drought tolerant, but watering the plants encourages healthier and faster growth. This ultimately leads to larger tubers to harvest later.
Dig up the tubers of cassava with a garden shovel after the plants have grown for at least eight months. Carefully pierce into the soil about 12 to 18 inches away from plant stem bases and lift the shovel blade. This diminishes chances of cutting into a tuber and helps you better seed the root system during the harvest. Wash off lingering clumps of soil from the tubers with water and allow them to air-dry.
Use the tubers, called yuca, within a day after harvest. Do not consume any part of the yuca until it has been peeled and appropriately boiled to remove toxic compounds. Peeled yuca roots submerged in water in the refrigerator or frozen will store for three to four months, according to the Center for Disease Control's website Fruits & Veggies Matter.