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When to Plant Petunia in Zone 12A

USDA Zone

12A

Cities Covered

25

Avg Last Frost

Friday, January 1, 2027

Plant Type

Indoor Start

📅 Planting Calendar for Zone 12A

Start Seeds Indoors Friday, October 23, 2026
Transplant Outdoors Friday, January 15, 2027

Pro Tip: Start Petunia seeds indoors 10 weeks before your last frost date for best results.

🌿 Plant Details

Scientific Name Petunia × hybrida
Days to Maturity 75 days
Sun Requirements Full Sun (6-8 hours)
Plant Spacing 12" apart

🤝 Companion Plants for Petunia

Good Companions

TomatoBasilMarigold

Avoid Planting Near

Fennel
See the full companion planting guide for Petunia →

Cities in Zone 12A

Other Plants for Zone 12A

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Growing Petunia in USDA Zone 12A

Petunia (Petunia × hybrida) grows well in USDA Hardiness Zone 12A. This zone includes cities like Aiea, Anahola, Haiku and 22 more.

The average last frost date for Zone 12A is around Friday, January 1, 2027. For best results, start your Petunia seeds indoors around Friday, October 23, 2026, then transplant outdoors around Friday, January 15, 2027.

Expect to harvest your Petunia approximately 75 days after planting.