How to Grow Oca
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Oca
Oxalis tuberosa
vegetableOca is a perennial tuber-producing plant native to the Andes mountains, cultivated for its small, potato-like edible tubers that range in color from yellow to red to purple. The plants produce attractive clover-like foliage with small yellow flowers. It thrives in cool climates and has been a staple crop in South American highlands for thousands of years.
When should you plant Oca in your zone?
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Example Oca timeline · Pittsburgh, PA (Zone 6b)
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Plant Oca
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Oca
Around Oct 14≈ 180 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Oca dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 8-9; can be grown as annual or perennial in mild climates
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Get my Oca timeline →Growth Stages
Sprouting
2-4 weeksSmall shoots emerge from planted tubers; first true leaves begin to unfold
Keep soil consistently moist. Maintain temperatures between 60-70°F for best sprouting. May take 2-4 weeks to emerge.
Vegetative Growth
6-10 weeksPlant develops bushy clover-like foliage on multiple stems reaching 12-18 inches tall; leaf area expands rapidly
Ensure consistent watering and moderate fertilization. Mulch around plants to retain moisture. Pinch back early growth if desired for bushier plants.
Flowering
4-8 weeksSmall yellow flowers appear at leaf axils; plant continues vegetative growth while beginning tuber initiation
Flowers are ornamental but not essential for tuber development. Maintain consistent moisture and moderate fertility. Cooler nights trigger better tuber formation.
Tuber Bulking
8-12 weeksUnderground tubers enlarge as plant matures; foliage may begin to yellow and senescence starts
Maintain consistent moisture as tubers develop. Reduce nitrogen fertilizer to avoid excessive leafy growth. Days must shorten and temperatures cool (below 70°F nights ideal) to trigger tuber bulking.
Maturity & Harvest
Variable based on climateFoliage dies back completely; tubers reach full size and are ready for harvest
Stop watering once foliage fully yellows. Allow 1-2 weeks after senescence for tubers to cure in the ground if frost is not expected.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Use row covers early; harvest promptly; store tubers at cool temperatures; rotate crops
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Encourage soil organisms; trap crops; thorough tilling; apply beneficial nematodes
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Increase humidity with misting; neem oil spray; remove affected foliage
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Strong water spray; insecticidal soap; encourage beneficial insects like ladybugs
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Ensure good air circulation; water at soil level; remove affected leaves; fungicide if severe
Uses
Staple Tuber Crop
CulinaryOca tubers are boiled, roasted, fried, or pureed like potatoes and have a slightly tart flavor. They are a traditional food staple in Andean countries and are gaining popularity in specialty markets worldwide. [source]
Sweet Flavor Enhancement
CulinaryWhen exposed to frost or stored in cool temperatures, oca tubers convert starch to sugars, developing a sweeter taste. This natural sweetening makes them delicious roasted or candied. [source]
Traditional Medicine
MedicinalIn South American traditional medicine, oca has been used to support digestion and provide nutritional supplementation. The plant contains oxalic acid, which has anti-inflammatory properties. [source]
Natural Dye Source
HouseholdThe colored tuber varieties (red and purple) can be used to create natural dyes for textiles and crafts, containing anthocyanin pigments. [source]
Pollinator Garden Addition
WildlifeThe small yellow flowers attract bees and other beneficial pollinators, making oca a dual-purpose crop that supports pollinator populations while producing food. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Harvest tubers 5-7 months after planting, once foliage has died back completely, typically in late autumn or early winter. Carefully dig around the plant to avoid damaging tubers. Tubers are ready when they reach 1-2 inches in diameter. For storage, cure tubers in a cool, dark place for 2-3 weeks, then store at 45-50°F in humid conditions (sand or sawdust). Can store for several months under proper conditions.
Fun Facts
- 🌱 Oca is the second most important tuber crop in the Andes after potatoes and has been cultivated for over 7,000 years by indigenous peoples.
- 🌱 The flavor of oca improves after frost; farmers traditionally left tubers in fields to be sweetened by cold temperatures before harvest and storage.
- 🌱 Oca tubers come in surprising colors including red, pink, yellow, white, and purple striped varieties, making them ornamentally interesting as well as nutritious.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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