Oca
Oxalis tuberosa · Oxalidaceae
📷 Frank Vincentz · CC BY-SA 3.0
⚠️ Truffette acide : oxalates solubles en concentration modérée dans tubercule et feuilles. Ingestion excessive provoque irritation buccale et troubles digestifs.
The gardener's calendar
Ideal time to plant oca: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Common name
- Oca, Tuberous Oxalis
- Family
- Oxalidaceae
- Type
- Tuberous herbaceous perennial
- Adult height
- 30 cm
- Foliage
- Deciduous (disappears in winter)
- Flowering
- June-July, yellow flowers
- Hardiness
- Frost-tender (mild to temperate climates)
- Origin
- Andes (Peru, Bolivia)
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability medium.
Expert tips
The key tip
Acid truffles are grown for their tubers: harvest in autumn and keep the soil fresh, not waterlogged.
The common mistake
Don't store them in a cool, dry place after harvest—they dry out and won't regrow.
The pro's trick
Sow the tubers 5 cm deep in August-September in a pot or aerated soil.
Care
Light
Place your oca in partial shade or filtered light. It tolerates light sun in cool climates, but prefers shelter from direct afternoon rays. A north or east-facing exposure is ideal to prevent scorched foliage in summer.
Watering
Keep the soil regularly moist during growth (April to September), without ever creating waterlogging. In winter, drastically reduce watering since the foliage dies back. Resting tubers require only minimal moisture.
Soil
Choose rich, well-draining soil that is slightly acidic. Enrich the soil with compost or leaf mold before planting. Compact or chalky soil can limit tuber development.
Fertilizing
Apply balanced fertilizer at the start of the growing season (spring) and repeat lightly mid-season. Avoid excess nitrogen, which would encourage foliage at the expense of tubers. Moderate fertilizing is more than sufficient.
Pruning and harvesting
No pruning is necessary. In autumn, when foliage naturally senesces, you can gently harvest the tubers for eating or leave the plant to rest in the ground in milder regions. Simply cut back dead foliage.
Diseases and pests
Oca is generally robust. Watch for tuber rot in case of excess moisture or poor drainage. Aphids may occasionally affect young spring foliage; a water spray is often enough to eliminate them.
Did you know?
Native to the high plateaus of the Andes, Oxalis tuberosa has been cultivated for millennia by Andean peoples under the name "oca" or local variants. Unlike the potato, its small tubers retain a crunchy texture and pleasant slight acidity in the mouth, characteristic of the Oxalidaceae family. In Europe, it remains an underappreciated vegetable garden curiosity, though it's gaining interest among chefs seeking original flavors and heritage crops.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
- Yellow sorrelOxalis corniculata
- Common wood sorrelOxalis stricta
- Oxalis perennansOxalis perennans
- Pink sorrelOxalis articulata
- Oxalis debilisOxalis debilis
- Slender yellow woodsorrelOxalis dillenii
Tips generated and checked by Viridia — adapt them to your local climate.