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When to Plant Rosemary in Zone 12B

USDA Zone

12B

Cities Covered

53

Avg Last Frost

Friday, January 1, 2027

Plant Type

Indoor Start

📅 Planting Calendar for Zone 12B

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

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

🌿 Plant Details

Scientific Name Salvia rosmarinus
Days to Maturity 120 days
Sun Requirements Full Sun (6+ hours)
Plant Spacing 24" apart

🤝 Companion Plants for Rosemary

Good Companions

BeanCabbageCarrotSage
See the full companion planting guide for Rosemary →

Cities in Zone 12B

Other Plants for Zone 12B

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Growing Rosemary in USDA Zone 12B

Rosemary (Salvia rosmarinus) grows well in USDA Hardiness Zone 12B. This zone includes cities like Captain Cook, Eleele, Ewa Beach and 50 more.

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

Expect to harvest your Rosemary approximately 120 days after planting.