Larkspur in Zone 10a & 10b
Consolida ajacis
Yes, larkspur grows in zones 10a and 10b. Plant it outside in Sep–Jan. For a fall crop, plant out in Sep–Jan.
When to plant larkspur 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.
| Window | Fall window |
|---|---|
| Start indoors | Not typically started indoors |
| Direct sow / transplant outside | Sep–Jan |
| Estimated bloom | ~95 days after direct-sowing |
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 3-4 ft.
Zone 10b dates sourced from growinginthegarden.com.
Fall window: the last sowing date is the average first frost minus days to maturity, the method in Purdue Extension's fall garden guide, which lists larkspur for late-summer planting.
Plant alongside it in zone 10b
These go outside within two weeks of larkspur in zone 10b, so one planting day can cover them.
- Bachelor's Button (Cornflower)Sep–Nov
- CalendulaSep–Nov
- DelphiniumSep–Nov
- Gaillardia (Blanket Flower)Sep–Nov
- PetuniaSep–Mar
- SnapdragonSep–Feb
Larkspur is one of the few flowers on this site that flatly refuses to be transplanted. It has to be direct-sown, and the seed won't germinate at all unless it's cold and kept dark, which puts it on the opposite schedule from most annuals people start indoors under lights. Get the timing right and it rewards you with tall, dense spires of bloom; get it wrong and the seed just sits in the ground doing nothing.
How larkspur fits zone 10's season
Zone 10b's frost-free window runs about 324 days, from January 30 to December 20. Larkspur needs about 95 days from sowing to first bloom.
Larkspur 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 |
|---|---|---|---|
| 2a & 2b | Not usually | Apr 22–Apr 29 | Jul 26–Aug 2 |
| 3a & 3b | Not usually | May 2–May 9 | Aug 5–Aug 12 |
| 4a & 4b | Not usually | Apr 17–Apr 24 | Jul 21–Jul 28 |
| 5a & 5b | Not usually | Apr 12–Apr 19 | Jul 16–Jul 23 |
| 6a & 6b | Not usually | Mar 28–Apr 4 | Jul 1–Jul 8 |
| 7a & 7b | Not usually | Mar 13–Mar 20 | Jun 16–Jun 23 |
| 8a & 8b | Not usually | Feb 25–Mar 4 | May 31–Jun 7 |
| 9a & 9b | Not usually | Jan 18–Jan 25 | Apr 23–Apr 30 |
| 10a & 10bFall window (your zone) | Not usually | Sep–Jan | ~95 days after direct-sowing |
Bloom dates are about 95 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 larkspur.
Where to buy larkspur seeds
Botanical Interests · True Leaf Market · High Mowing Organic Seeds (each supplier's larkspur seeds)
Varieties we recommend, and where to get them:
- Misty Lavender: Johnny's describes pearly gray-lavender blooms, identical in their trials to the heirloom 'Earl Grey', on the same 9-12 inch flower spikes as QIS. Buy: Botanical Interests Full notes
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 larkspur" 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 Larkspur in USDA zone 10b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
Save to Pinterest