Oxalis tuberosa
Oca
Common names: Tuberous oxalis, Andean oxalis
At a glance
- Light
- Full sun
- Spacing
- 30 cm, rows 60 cm
- Lifespan
- Perennial
- Planting
- Apr–May
- Harvest
- Oct–Nov
- Hardiness
- Cold damage below −1 °C
- Water need
- Medium
Photo: Frank Vincentz · CC BY-SA 3.0 · Source
This description was machine-translated.
Description
Oxalis tuberosa, commonly known as Oca, is a tuberous plant native to the Andes. It produces colorful, cylindrical tubers underground in shades of yellow, pink, or red. Above ground, it forms a loose shrub with small, leaf‑like blades that fold together in the evening. Tubers begin forming only after the days shorten in autumn, so harvest occurs after the first mild frosts, typically late October to November. Raw tubers have a pleasantly tart flavor; cooked they become milder, resembling potatoes with a lemony note.
Care instructions
Plant sprouted tubers after the last frost (around mid‑May, week 20) spaced about 30 cm apart in loose, humus‑rich soil. Oca prefers a sunny to partially shaded position and consistent moisture, but the tubers should not sit in standing water. In summer, mound soil around the plants as you would with potatoes; this encourages tuber development and protects the base from light. Because tubers swell only after short days in autumn, be patient until October. When the foliage dies back after the first frost, carefully dig up the tubers. Store harvested tubers in a cool, frost‑free place, such as a box with slightly damp sand in a cellar.
The care notes were machine-translated from German.
Garden year
PlantingApr–May
HarvestOct–Nov
Soil & site
Soil pH
Soil type
well-drained, humus-rich, nutrient-rich, loamy
Oca likes loose, humus-rich soil that drains water well, because standing wet makes the tubers rot. A medium to slightly acidic pH of 5.5 to 6.8 suits it best. Before planting, the soil welcomes mature compost, so that it stays loose and supports tuber formation in autumn.
Feeding
Medium feeder
Months
May–Jul
At planting in May, dig in mature compost or well-rotted manure; that is enough for the start. In June and July, you can top up with a portion of compost or diluted nettle liquid feed to promote leaf growth. From August, feed more sparingly, so that the plant puts its energy into tuber formation rather than foliage.
Overwintering
Oca is frost-sensitive and is grown as an annual in our latitudes. As soon as the first frost blackens the foliage, harvest the tubers and store them cool and dark, best packed in sand or soil at 4 to 8 degrees. For the next season, keep a few healthy tubers back as seed tubers.
Propagation
Methods
- Offsets
- Division
Propagation is by the tubers, which you plant in spring from mid-May · week 20, as soon as frosts no longer threaten. Larger tubers can be divided into two or three pieces before planting, as long as each piece has an eye. Set the pieces about 8 to 10 cm deep and 30 to 40 cm apart in loose soil. Tuber formation only begins with the shorter days in late summer, so oca needs a long, frost-free season.
For your garden
Grow Oca yourself
Gartenkern tells you when frost is coming, when to sow and when to harvest, for your location.
Free, no time limit
Notes from real gardens
What other gardeners have written down about this variety, anonymous and voluntary.
No notes shared yet. Will you be the first to write one down?