Borage in Zone 10a & 10b
Borago officinalis
Yes, borage grows in zones 10a and 10b. Plant it outside Jan 30–Feb 6.
When to plant borage in zone 10b
Zones 10a and 10b 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 | Jan 30–Feb 6 |
| Estimated harvest | Mar 26–Apr 2 (~55 days after direct-sowing) |
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 1.5-3 ft.
Plant alongside it in zone 10b
These go outside within two weeks of borage in zone 10b, so one planting day can cover them.
- BasilFeb–Aug
- RosemaryFeb–Apr
- AniseJan 30–Feb 6
- Dandelion (Cultivated)Jan 30–Feb 6
- EpazoteJan 30–Feb 6
- Licorice MarigoldJan 30–Feb 6
Borage is a fuzzy-leaved annual herb best known for its star-shaped blue flowers and mild, cucumber-like flavor. Both the young leaves and flowers are edible, and few plants pull in bees as reliably.
How borage fits zone 10's season
Zone 10b's frost-free window runs about 324 days, from January 30 to December 20. Borage needs about 55 days from sowing to first harvest.
Borage planting windows in every zone
Zone 10b is highlighted. Useful for comparing against a neighbouring zone, or for a garden somewhere else.
| Zone | Start indoors | Sow or plant out | Harvest |
|---|---|---|---|
| 2a & 2b | Not usually | May 20–May 27 | Jul 14–Jul 21 |
| 3a & 3b | Not usually | May 30–Jun 6 | Jul 24–Jul 31 |
| 4a & 4b | Not usually | May 15–May 22 | Jul 9–Jul 16 |
| 5a & 5b | Not usually | May 10–May 17 | Jul 4–Jul 11 |
| 6a & 6b | Not usually | Apr 25–May 2 | Jun 19–Jun 26 |
| 7a & 7b | Not usually | Apr 10–Apr 17 | Jun 4–Jun 11 |
| 8a & 8b | Not usually | Mar 25–Apr 1 | May 19–May 26 |
| 9a & 9b | Not usually | Feb 15–Feb 22 | Apr 11–Apr 18 |
| 10a & 10b (your zone) | Not usually | Jan 30–Feb 6 | Mar 26–Apr 2 |
Harvest dates are about 55 days after the sow or plant-out date.
Zone 2 sows before zone 3 here, which looks wrong and is not. USDA zones rank winter cold, not season length, and zone 2 is mostly interior Alaska, where hard winters come with warm summers. More on what a zone measures.
Good companions
No well-established companions for borage.
Where to buy borage seeds
Botanical Interests · True Leaf Market · Burpee (each supplier's borage seeds)
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing borage" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 10b calendar · Plan your beds in the Garden Designer →
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Growing Borage in USDA zone 10b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
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