How Yuca Root Grows

Plant Features

• Native to Paraguay and Brazil, cassava sprouts an upright stalk that is lined with long-stemmed, glossy dark green leaves. The compound leaf comprises numerous slender pointy lobes that look like an open, multifingered hand. As the plant grows over the year in warm, moist soil, the food made in the leaves from photosynthesis are transported to the underground tubers -- the yuca roots -- causing them to enlarge or branch. Cassava is an evergreen shrub but is temporarily killed back by seasonal drought or onset of light winter frosts.

Types

• Originally, when Europeans learned of cassava from indigenous South American peoples, botanists believed cassava plants were either "sweet rooted" or "bitter rooted." Today, taxonomists group them both into species Manihot esculenta, but only those plants that produced tuberous roots containing lower levels of hydrocyanic glycosides, a toxin, are grown in gardens and fields for food. Boiling the tubers of either plant kind removes the toxins, and usually the tan to purplish tuber skin contains the most toxins, and therefore is peeled off before boiling.

Planting Cassava

• Because the roots of cassava are a food starch, the roots are preserved and stored and not used for plant propagation. Instead, plants are chopped down and stem cuttings measuring 6 to 14 inches long are made with at least one node present. Plant them 3 to 6 inches deep in the soil, with one-half the cutting above ground oriented vertically or at an angle. The stem cuttings sprout roots in the warm, moist soil and the dormant buds on the above-ground tissues sprout leaves and branches. As the plants grow over several months, the roots fatten and become starch-storing tubers.

Harvest

• Cassava plants grow in the garden for eight to 12 months before being pulled up to harvest the tubers. Plants may be left in the ground indefinitely, dying back in winter or left to grow into more massive shrubs, but the tubers become overly large, fibrous and tough -- not ideal for food preparation. The plant is pulled up, the roots cut off and stored, and stem cutting immediately made from the upper portions of the plant and immediately replanted in the garden.