When should I plant Rosemary in Zone 10a?

Start Rosemary seeds indoors around Dec 12. Transplant outdoors after Feb 27. Expect first harvest around May 28.

What is the last frost date for Zone 10a?

The average last spring frost date for Zone 10a is Feb 20. The first fall frost averages Dec 1, giving a 284-day growing season.

Can I grow Rosemary in Zone 10a?

Yes. Rosemary needs 90 days to harvest. Zone 10a has a 284-day growing season, which is sufficient.

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🌿 Growing Rosemary in Zone 10a

Zone 10a has a year-round growing season. Rosemary can be planted almost any time with proper planning. Last frost: Feb 20. First frost: Dec 1.

Planting Calendar

Indoor

Outdoor

Harvest

Dec 12Dec 1

Season: Feb 20 – Dec 1 (284 days)

Zone10a

Last FrostFeb 20

First FrostDec 1

Season Length284 days

Days to Harvest90

SunFull Sun

Frost ToleranceLight

Spacing1/sqft (12" apart)

When to Plant Rosemary in Zone 10a

Start Seeds Indoors: Dec 12

Start Rosemary seeds indoors around Dec 12 (10 weeks before last frost). Optimal germination temperature: 70°F. Germinates in 14–28 days.

Transplant Outdoors: Feb 27

Transplant Rosemary seedlings outdoors after Feb 27. Wait until soil temperature reaches 55°F. Space plants at 1/sqft (12" apart). Harden off plants for a week before moving outside.

Harvest: May 28

First harvest approximately May 28 (~90 days from transplant). Continue harvesting until first frost (Dec 1). Rosemary can overwinter in mild climates for continued harvest.

Companion Planting

✅ Beans✅ Carrots✅ Cabbage

Rosemary in Other Zones

1a 1b 2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a 11b 12a 12b 13a 13b

Plan Your Rosemary Garden

Track Rosemary from seed to harvest with personalized frost dates, watering recommendations, and companion planting visualization.

Start Free Rosemary Growing Guide