Petunia in Zone 11a & 11b
Petunia × hybrida
When to plant petunia in zone 11b
Zones 11a and 11b share the same average frost dates in our data, so this page covers both.
Method: Start indoors: Start indoors from seed, then transplant outside. Petunia needs a head start most zones can't give it by direct-sowing alone.
| Start indoors | Oct 30–Nov 6 |
|---|---|
| Direct sow / transplant outside | Jan 15–Jan 22 |
| Estimated bloom | Mar 26–Apr 2 (~70 days after transplanting) |
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 0.5-1 ft.
Petunias take the longest lead time of any flower on this list. Seed goes in about 9 weeks before last frost, and it needs light to germinate, so it's surface-sown rather than buried. That long runway is the price for having sizable, blooming plants ready to set out once the weather turns: a trailing or mounding 6- to 12-inch plant covered in trumpet-shaped flowers across a wide color range.
How petunia fits zone 11's season
Zone 11b is frost-free in this dataset, so frost is not what limits the calendar here. What you can plant, and when, comes down to summer heat and daylength instead.
Good companions
No standout companions recorded yet for Petunia.
Where to buy petunia seeds
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing petunia" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 11b calendar · Full companion planting guide · Full plant profile · Plan your beds in the Garden Designer →
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Growing Petunia in USDA zone 11b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
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