Cassava: Growing Guide for Kauaʻi

Overview

Cassava is one of the world’s most important staple foods. It grows in poor soil and through drought, and its starchy roots can stay in the ground for months until you need them, making it a valuable food-security crop.

History

Cassava was domesticated in South America thousands of years ago and spread across the tropics after the 1500s. It is a staple in Africa, Asia, Latin America, and the Pacific, and is grown in many Hawaiʻi gardens.

Growing on Kauaʻi

Thrives in sun and handles poor soil and dry spells once established.
Needs good drainage; roots rot in waterlogged soil. On wet sites, plant on mounds.

Planting and propagation

Cut mature, woody stems into pieces 8–12 inches long with several buds.
Plant them upright or at an angle, about two-thirds buried, right way up, roughly 3 ft apart.
Keep moist until new leaves appear.

Care and maintenance

Mulch and weed while young; after that it needs little care.
Save stems from harvested plants to replant.

Role in the guild

Cassava fills the sunny shrub layer of a staple-focused guild, alongside breadfruit, banana, and sweet potato. Its leaves drop and add to the mulch layer.

Harvest

Roots are usually ready 8–12 months after planting. Loosen the soil and pull the whole plant. Harvest only what you can use within a day or two, since roots spoil quickly once out of the ground; leave the rest growing.

Uses

Food: peeled, boiled roots eaten like potato, fried, mashed, or made into flour and tapioca.
Soil: leaves and stems add mulch.

Important caution

Never eat cassava raw. All cassava contains compounds that release cyanide. Peel the roots completely, then boil until fully soft and discard the cooking water. “Bitter” varieties need more thorough processing than “sweet” ones; if you don’t know which you have, treat it as bitter. Leaves, if eaten, must be well cooked.

Problems to watch

Root rot in waterlogged soil.
Mites and mealybugs in dry weather.

General guidance for Kauaʻi; conditions vary by site. Check any new plant at plantpono.org before planting.