Osteospermum in Zone 10a & 10b
Osteospermum ecklonis
Yes, osteospermum grows in zones 10a and 10b. Start seeds indoors Dec 5–Dec 12 and plant out Feb 6–Feb 13.
When to plant osteospermum in zone 10b
Zones 10a and 10b 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 5–Dec 12 |
|---|---|
| Direct sow / transplant outside | Feb 6–Feb 13 |
| Estimated bloom | May 7–May 14 (~90 days after transplanting) |
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 1-3 ft.
Plant alongside it in zone 10b
These go outside within two weeks of osteospermum in zone 10b, so one planting day can cover them.
- MarigoldFeb–May
- Ageratum (Flossflower)Feb 6–Feb 13
- AmaryllisFeb 6–Feb 13
- Annual Geranium (Pelargonium)Feb 6–Feb 13
- Calla LilyFeb 6–Feb 13
- Campanula (Bellflower)Feb 6–Feb 13

Two different plants are sold as African daisy, and knowing which you have decides how you treat it.
How osteospermum fits zone 10's season
Zone 10b's frost-free window runs about 324 days, from January 30 to December 20. Osteospermum needs about 90 days from transplant to first bloom.
Osteospermum 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 | Bloom |
|---|---|---|---|
| 4a & 4b | Mar 20–Mar 27 | May 22–May 29 | Aug 20–Aug 27 |
| 5a & 5b | Mar 15–Mar 22 | May 17–May 24 | Aug 15–Aug 22 |
| 6a & 6b | Feb 28–Mar 7 | May 2–May 9 | Jul 31–Aug 7 |
| 7a & 7b | Feb 13–Feb 20 | Apr 17–Apr 24 | Jul 16–Jul 23 |
| 8a & 8b | Jan 28–Feb 4 | Apr 1–Apr 8 | Jun 30–Jul 7 |
| 9a & 9b | Dec 21–Dec 28 | Feb 22–Mar 1 | May 23–May 30 |
| 10a & 10b (your zone) | Dec 5–Dec 12 | Feb 6–Feb 13 | May 7–May 14 |
Bloom dates are about 90 days after the sow or plant-out date, not after starting seeds indoors.
Good companions
No well-established companions for osteospermum.
Where to buy osteospermum seeds
True Leaf Market (each supplier's osteospermum seeds)
See why we recommend these suppliers →
As an Amazon Associate we earn from qualifying purchases. Some links on this page also go to other retailers we may earn a commission from as an affiliate, at no extra cost to you. We only recommend products with a clear consensus of positive, independent reviews, or ones we bought and use ourselves. Each item on our gear page says which.
See it growing
Search YouTube for "growing osteospermum" 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 →

Pin this for later
Growing Osteospermum in USDA zone 10b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
Save to Pinterest