Marigold in Zone 10a & 10b
Tagetes
Yes, marigold grows in zones 10a and 10b. Start seeds indoors in Jan–Apr and plant out in Feb–May. For a fall crop, start seeds indoors in Aug–Sep and plant out in Sep–Oct.
When to plant marigold 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. In your zone it needs a head start on the heat that direct-sowing elsewhere doesn't require.
| Window | Spring window |
|---|---|
| Start indoors | Jan–Apr |
| Direct sow / transplant outside | Feb–May |
| Estimated bloom | ~50 days after transplanting |
| Window | Fall window |
|---|---|
| Start indoors | Aug–Sep |
| Direct sow / transplant outside | Sep–Oct |
| Estimated bloom | ~50 days after transplanting |
Spacing: 4 per square foot (square-foot-gardening spacing). Mature height: 0.5-1 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 marigold for late-summer planting.
Plant alongside it in zone 10b
These go outside within two weeks of marigold in zone 10b, so one planting day can cover them.
- DahliaFeb–Apr
- SunflowerFeb–Aug
- African DaisyJan 30–Feb 6
- Amaranthus (Love-Lies-Bleeding)Jan 30–Feb 6
- Ammi (False Queen Anne's Lace)Jan 30–Feb 6
- Ammobium (Winged Everlasting)Jan 30–Feb 6

Marigolds earn their place in a vegetable garden on function more than looks, though the looks aren't bad either: compact mounded plants under a foot tall, covered in ruffled gold, orange, or bicolor blooms from early summer to frost. They're grown here as a companion planting tool for pest suppression, not as something you'll harvest and eat.
How marigold fits zone 10's season
Zone 10b's frost-free window runs about 324 days, from January 30 to December 20. Marigold needs about 50 days from sowing to first bloom.
Marigold 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 | Apr 8–Apr 15 | May 27–Jun 3 | Jul 16–Jul 23 |
| 3a & 3b | Apr 18–Apr 25 | Jun 6–Jun 13 | Jul 26–Aug 2 |
| 4a & 4b | Apr 3–Apr 10 | May 22–May 29 | Jul 11–Jul 18 |
| 5a & 5b | Mar 29–Apr 5 | May 17–May 24 | Jul 6–Jul 13 |
| 6a & 6b | Mar 14–Mar 21 | May 2–May 9 | Jun 21–Jun 28 |
| 7a & 7b | Feb 27–Mar 6 | Apr 17–Apr 24 | Jun 6–Jun 13 |
| 8a & 8b | Feb 11–Feb 18 | Apr 1–Apr 8 | May 21–May 28 |
| 9a & 9b | Jan 4–Jan 11 | Feb 22–Mar 1 | Apr 13–Apr 20 |
| 10a & 10bSpring window (your zone) | Jan–Apr | Feb–May | ~50 days after transplanting |
| Fall window | Aug–Sep | Sep–Oct | ~50 days after transplanting |
| 11a & 11b | Nov 20–Nov 27 | Jan 8–Jan 15 | Feb 27–Mar 6 |
Bloom dates are about 50 days after the sow or plant-out date, not after starting seeds indoors.
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
- Tomato: UF/IFAS Extension confirms French marigold is effective against a wide range of root-knot nematode species: a real, documented effect, not folklore. The insect-pest-deterrent half of this claim is less well documented.
- Zucchini: An Iowa State study found marigold (alongside nasturtium) reduced squash bug and cucumber beetle damage when planted near squash, a real trap-crop/deterrent effect rather than folklore.
Where to buy marigold seeds
Botanical Interests · True Leaf Market · Burpee · High Mowing Organic Seeds (each supplier's marigold 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 marigold" 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 Marigold in USDA zone 10b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
Save to Pinterest