How to grow Cassava

Where to plant

Cassava needs heat, full sun and a long frost free season, 8 to 11 months, to form usable roots. It grows in light, well drained soil and copes with poor ground, but not with waterlogging.

It is grown in South Florida, where it can be planted for much of the year, in Central Florida in spring, in Southern California from spring into summer, and all year in Hawaii. In North Florida, the Gulf South, Texas, the desert and the rest of the country, the frost free season is too short for a root crop, although it can be grown as an ornamental and dug in fall for a small harvest.

Choosing a variety

Cassava is divided into sweet and bitter types. Sweet types have low levels of the compounds that release cyanide and are the ones grown for boiling as a vegetable; bitter types need careful processing. For home gardens, start from cuttings of a known sweet type, often sold or shared locally.

How to plant

1. Prepare the bed as you would for sweet potatoes, with some compost and good drainage.
2. Cut mature stems into pieces about 10 inches (25 cm) long, each with several buds.
3. Plant the pieces right way up, at an angle or upright, 2 to 4 inches (5 to 10 cm) deep, about 4 feet (1.2 m) apart.
4. Water to settle the soil. Shoots usually appear within a couple of weeks in warm weather.
5. Keep weeds down until the plants shade the ground.

Watering and feeding

Water regularly while the cuttings establish. Once growing, cassava is drought tolerant, though it yields better with occasional deep watering in long dry spells. Avoid soggy soil, which rots the roots.

UF/IFAS gives cassava a medium need for nitrogen, phosphate and potash. In a garden, prepare the bed as for sweet potatoes and give a balanced fertilizer a month or two after planting and again about four months after planting.

Pruning and care through the year

• Keep weeds down early; cassava grows slowly at first and early weed competition is the most damaging.
• Draw soil up along the rows as the plants grow; the ridges give the roots room to form and improve drainage.
• Use cuttings only from healthy plants, as bacterial blight and other problems travel on cuttings. Federal rules prohibit importing cassava cuttings or seed from abroad.
• Save some healthy mature stems at harvest for the next planting.

Harvesting

Dig the roots about 8 to 12 months after planting. Each plant forms a cluster of four to eight roots, typically 1 to 4 inches (2.5 to 10 cm) thick and 8 to 15 inches (20 to 38 cm) long. Loosen the soil and pull the plant up by the stem.

Cassava has no fixed maturity date and keeps growing while it has leaves. Fresh roots are very perishable, so dig only what you will use. In frost free areas, leave the rest in the ground until needed, and where frost comes, dig before or soon after a killing frost.

Using it

The thin reddish brown bark and the layer just beneath it hold most of the cyanide forming compounds. Peel the roots thickly with a knife, wash them and cook them thoroughly, by boiling, before eating or frying. Leaves can be eaten too, but only well boiled, never raw.

Propagation and saving seed

Cassava is grown from stem cuttings, which root readily. A piece of stem about 10 inches long, buried a few inches deep in warm, moist soil or potting mix, will sprout and can be planted out.