fruit vegetable

Oca

Oxalis tuberosa

The Story

Plant Bio

Oxalis tuberosa, commonly known as oca, is a low-growing, spreading herbaceous perennial from the Andes that forms a dense mound of succulent stems and clover-like foliage. The trifoliolate leaves are photosensitive, folding downward at night, and are accompanied by small, yellow, five-petaled flowers borne on slender stalks from summer through fall.

This species produces edible, starch-rich underground tubers in late fall as day lengths shorten. The tubers develop in a variety of colors and have a tangy flavor due to oxalic acid, which decreases significantly after exposure to sunlight or cooking.

Uses & Benefits:

Forms a lush, dense groundcover of attractive, shamrock-like foliage that folds up at night.

Produces highly nutritious, edible tubers that can be eaten raw, boiled, baked, or roasted.

Yellow flowers provide a nectar source for generalist native pollinating insects during summer.

Essentials

At a Glance

Plant Type

Fruit Vegetable

Height

20"

Width

35"

Light

Full Sun, Partial Sun

Zones

6, 7, 8, 9

Water

Medium

Humidity

Moderate

Lifespan

Perennial

Native To

South America

Toxicity

Contains oxalic acid; caution for kidney stones

Bloom period

Summer – Fall

In flower about 6 months of the year

Planting

How to Grow

Plant whole tubers or pieces with one to three active eyes two inches deep in light, well-drained soil after the last hard spring frost.
Maintain consistent soil moisture throughout the summer to support steady vegetative growth and prevent stem dieback.
Mound soil or organic mulch around the base of the stems in mid-summer to encourage maximum underground tuber development.
Harvest the tubers carefully in late fall after frost has killed the top growth, then expose them to sunlight for several days to sweeten.

Pro Tip

Delay harvesting until late fall after a hard frost blackens the foliage; tubers only begin to bulk rapidly in response to the short days of late fall, and early harvesting drastically reduces yield.

Keep It Thriving

Care Guide

Do

Hill soil around the growing stems mid-season to increase the space available for tuber formation.
Provide regular irrigation during dry summer periods to ensure even tuber development.
Store harvested tubers in a cool, dark, well-ventilated space to prevent premature sprouting.

Don't

Do not apply high-nitrogen fertilizers, which stimulate excessive leaf growth at the expense of tuber yield.
Do not plant in heavy, poorly drained clay soils where standing water will cause the tubers to rot.
Do not harvest early in fall before the short-day photoperiod triggers tuber development.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Harvest
Mulch
Plant
Winter Prep

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Edible GardenGroundcoverContainer Planting

Companion Plants

Solanum tuberosum Tropaeolum majus Helianthus tuberosus

Multiply

Propagation Methods

Good to Know

Common Questions

Oca questions

What zones can Oca grow in?

Oca is hardy in USDA Zones 6–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

When does Oca bloom?

Oca typically blooms in summer through fall. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Oca need full sun?

Oca does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.