Oxalis tuberosa
Common name: Oca · New Zealand yam · Uqa
Oxalis tuberosa is a herbaceous perennial of the wood-sorrel family, domesticated in the central Andes of South America, where it has been grown for centuries for its edible tubers. It forms clover-like leaves and small yellow flowers, and produces brightly colored tubers in shades of red, pink, yellow, and white. It is one of the most important root crops of the high Andes after the potato, and is also cultivated commercially in New Zealand.
Care summary
Sun
Full sun to light shade; cool climates preferred
Water
Regular moisture while growing; avoid waterlogging
Soil
Fertile, loose, well-drained soil
Hardiness
Zones 8–10 (tubers frost-tender)
Mature height
About 20–30 cm (0.7–1 ft)
Pet safe
No — contains oxalates, risky for pets if eaten
Difficulty
Moderate
Propagation
Propagate from tubers, which is how this crop is normally grown. Plant whole healthy tubers, or cut larger ones into pieces each bearing at least one bud, about 5 cm deep in loose, fertile soil once frost danger has passed; tubers form only as days shorten in autumn.
Fun facts
- Oca is a staple root crop in the Andes, second only to the potato in importance there.
- It is usually grown in New Zealand and marketed there as "New Zealand yam," though it is not a true yam.
- The tubers contain oxalic acid; Andean farmers traditionally expose them to sun and frost to reduce acidity.
- Tubers come in vivid colors — red, pink, orange, yellow, and white — often with contrasting eyes.