Zucchini in Zone 9a & 9b
Cucurbita pepo
Yes, zucchini grows in zones 9a and 9b. Start seeds indoors Jan 25–Feb 1 and plant out Feb 22–Mar 1.
When to plant zucchini in zone 9b
Zones 9a and 9b share the same average frost dates, so this page covers both.
Method: Either: Start indoors for an earlier harvest, or direct-sow outside for less fuss. Either works.
| Start indoors | Jan 25–Feb 1 |
|---|---|
| Direct sow / transplant outside | Feb 22–Mar 1 |
| Estimated harvest | Apr 13–Apr 20 (~50 days after planting) |
Spacing: about 4 square feet per plant (square-foot-gardening spacing). Mature height: 2-3 ft.
Plant alongside it in zone 9b
These go outside within two weeks of zucchini in zone 9b, so one planting day can cover them.
- TomatoMar 1–Mar 8
- Bush BeansFeb 22–Mar 1
- Sweet CornFeb 22–Mar 1
- CucumberFeb 22–Mar 1
- Winter SquashFeb 22–Mar 1
- BroccoliniFeb 15–Feb 22
Zucchini's reputation for overwhelming a garden is well-earned: a single healthy plant can produce more squash than most households can eat, which is exactly why our planting calendar puts just one plant per square foot rather than clustering several together.
How zucchini fits zone 9's season
Zone 9b's frost-free window runs about 293 days, from February 15 to December 5. Zucchini needs about 50 days from sowing to first harvest.
Zucchini 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 | May 9–May 16 | Jun 6–Jun 13 | Jul 26–Aug 2 |
| 4a & 4b | Apr 24–May 1 | May 22–May 29 | Jul 11–Jul 18 |
| 5a & 5b | Apr 19–Apr 26 | May 17–May 24 | Jul 6–Jul 13 |
| 6a & 6b | Apr 4–Apr 11 | May 2–May 9 | Jun 21–Jun 28 |
| 7a & 7b | Mar 20–Mar 27 | Apr 17–Apr 24 | Jun 6–Jun 13 |
| 8a & 8b | Mar 4–Mar 11 | Apr 1–Apr 8 | May 21–May 28 |
| 9a & 9b (your zone) | Jan 25–Feb 1 | Feb 22–Mar 1 | Apr 13–Apr 20 |
| 10a & 10bSpring window | Jan–Feb | Feb–Mar | ~50 days after transplanting |
| Summer window | Jul–Aug | Aug–Sep | ~50 days after transplanting |
| 11a & 11bSummer window | Not usually | Aug–Mar | ~50 days after planting |
Harvest dates are about 50 days after the sow or plant-out date, not after starting seeds indoors.
Good companions
- Marigold: Marigolds deter squash bugs and beetles.
- Nasturtium: Nasturtium is a trap crop that draws aphids away from squash.
Where to buy zucchini seeds
True Leaf Market · Burpee · High Mowing Organic Seeds (each supplier's zucchini seeds)
Varieties we recommend, and where to get them:
- Dunja (F1, Organic): Johnny's Seeds describes it as early and powdery-mildew resistant, worth considering in humid climates where PM regularly cuts a zucchini season short. Buy: High Mowing Organic Seeds Full notes
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing zucchini" 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 Zucchini in USDA zone 9b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
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