Aji Amarillo Pepper in Zone 9a & 9b
Capsicum baccatum
Yes, aji amarillo pepper grows in zones 9a and 9b. Start seeds indoors Dec 7–Dec 14 and plant out Mar 1–Mar 8.
When to plant aji amarillo pepper in zone 9b
Zones 9a and 9b share the same average frost dates, so this page covers both.
Method: Start indoors: Start indoors from seed, then transplant outside. It needs a head start most zones can't give it by direct-sowing alone.
| Start indoors | Dec 7–Dec 14 |
|---|---|
| Direct sow / transplant outside | Mar 1–Mar 8 |
| Estimated harvest | May 30–Jun 6 (~90 days after transplanting) |
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 2.5-3.5 ft.
Plant alongside it in zone 9b
These go outside within two weeks of aji amarillo pepper in zone 9b, so one planting day can cover them.
- Bell PepperMar 1–Mar 8
- 7 Pot Douglah Pepper (Chocolate 7 Pot)Mar 1–Mar 8
- 7 Pot Primo PepperMar 1–Mar 8
- Anaheim Pepper (New Mexico, Hatch)Mar 1–Mar 8
- Carolina Reaper PepperMar 1–Mar 8
- Cayenne PepperMar 1–Mar 8

Aji amarillo is the yellow-orange chile at the center of Peruvian cooking. It is *Capsicum baccatum*, a different species from bells and jalapeños, known for fruity, citrusy flavor.
How aji amarillo pepper fits zone 9's season
Zone 9b's frost-free window runs about 293 days, from February 15 to December 5. Aji amarillo pepper needs about 90 days from transplant to first harvest.
Aji Amarillo Pepper 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 |
|---|---|---|---|
| 3a & 3b | Mar 21–Mar 28 | Jun 13–Jun 20 | Sep 11–Sep 18 |
| 4a & 4b | Mar 6–Mar 13 | May 29–Jun 5 | Aug 27–Sep 3 |
| 5a & 5b | Mar 1–Mar 8 | May 24–May 31 | Aug 22–Aug 29 |
| 6a & 6b | Feb 14–Feb 21 | May 9–May 16 | Aug 7–Aug 14 |
| 7a & 7b | Jan 30–Feb 6 | Apr 24–May 1 | Jul 23–Jul 30 |
| 8a & 8b | Jan 14–Jan 21 | Apr 8–Apr 15 | Jul 7–Jul 14 |
| 9a & 9b (your zone) | Dec 7–Dec 14 | Mar 1–Mar 8 | May 30–Jun 6 |
| 10a & 10b | Nov 21–Nov 28 | Feb 13–Feb 20 | May 14–May 21 |
| 11a & 11bSummer window | May–Nov | Aug–Feb | ~90 days after transplanting |
Harvest dates are about 90 days after the sow or plant-out date, not after starting seeds indoors.
Good companions
- Basil: Reputed to repel aphids and improve pepper growth nearby, but a controlled garden trial testing this same claim on a related crop found no pest-reduction benefit from basil, and found higher pest counts on the basil-companioned plants. Treat this pairing as unproven, not as a working pest deterrent.
- Onion: Reputed to deter many common pepper pests, though this specific pairing hasn't been tested the way onion/carrot pest-masking has. Treat it as garden tradition.
Where to buy aji amarillo pepper seeds
None of the seed suppliers we list carries aji amarillo pepper 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 aji amarillo pepper" 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 Aji Amarillo Pepper in USDA zone 9b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
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