Oca in Zone 9a & 9b
Oxalis tuberosa
Yes, oca grows in zones 9a and 9b. Plant it outside Feb 15–Feb 22.
When to plant oca in zone 9b
Zones 9a and 9b share the same average frost dates, so this page covers both.
Method: Direct sow: Direct-sow outside. It doesn't transplant well, or doesn't need the extra time indoors.
| Start indoors | Not typically started indoors |
|---|---|
| Direct sow / transplant outside | Feb 15–Feb 22 |
| Estimated harvest | Sep 13–Sep 20 (~210 days after direct-sowing) |
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 0.5-1.5 ft.
Plant alongside it in zone 9b
These go outside within two weeks of oca in zone 9b, so one planting day can cover them.
- CabbageFeb 1–Feb 8
- TomatoMar 1–Mar 8
- Bush BeansFeb 22–Mar 1
- Sweet CornFeb 22–Mar 1
- LettuceFeb 1–Feb 8
- CucumberFeb 22–Mar 1
Oca is an Andean tuber crop, a relative of potato with vividly colored roots in reds, yellows, and oranges, and a genuine growing quirk that sets it apart from anything else here.
How oca fits zone 9's season
Zone 9b's frost-free window runs about 293 days, from February 15 to December 5. Oca needs about 210 days from sowing to first harvest.
Oca planting windows in every zone
Zone 9b is highlighted. Useful for comparing against a neighbouring zone, or for a garden somewhere else.
| Zone | Start indoors | Sow or plant out | Harvest |
|---|---|---|---|
| 6a & 6b | Not usually | Apr 25–May 2 | Nov 21–Nov 28 |
| 7a & 7b | Not usually | Apr 10–Apr 17 | Nov 6–Nov 13 |
| 8a & 8b | Not usually | Mar 25–Apr 1 | Oct 21–Oct 28 |
| 9a & 9b (your zone) | Not usually | Feb 15–Feb 22 | Sep 13–Sep 20 |
Harvest dates are about 210 days after the sow or plant-out date.
Good companions
No well-established companions for oca.
Where to buy oca seeds
None of the seed suppliers we list carries oca seeds right now. A local garden center or a specialty seed house is the place to look.
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing oca" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 9b calendar · Plan your beds in the Garden Designer →
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Growing Oca in USDA zone 9b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
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