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When to Plant Rosemary in USDA Zone 9a

Zone 9a Zone 9a April

Top priorities for Zone 9a gardeners in April

April rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Zone 9a.

Avg. last frost March 4
Avg. first frost November 24
Get the full Zone 9a Garden Planner — free →
Rosemary

Rosemary is an aromatic evergreen shrub with needle-like leaves and a piney, citrus flavor. It is a Mediterranean herb that thrives in warm, dry conditions.

In Zone 9a, the average last spring frost is around February 10 and the first fall frost is around December 10, giving you a growing season of approximately 303 days.

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Zone 9a Year-round
303 days
Last Spring Frost February 10
303 growing days
First Fall Frost December 10

Rosemary Planting Timeline — Zone 9a

Where Is USDA Zone 9a?

The map below highlights the states that contain Zone 9a. Click any state to see the Rosemary planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Rosemary Planting Calendar — Zone 9a

Activity When Date Range
Transplant Outdoors February 17 Feb 17 – Mar 3
Harvest May 12 May 12 – Sep 29

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Transplant Outdoors
March Transplant Outdoors
April
May Harvest
June Harvest
July Harvest
August Harvest
September Harvest
October
November
December

Free Zone 9a Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 9a with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Low — drought tolerant

Days to Maturity

80–180 days

Soil pH

6 – 7.5

Zone Temperature Range

°F to °F average annual minimum

Growing Season

303 days (Zone average)

Planting Specifications

Planting Depth0.5 inches
Plant Spacing8 inches apart
Row Spacing12 inches between rows

Succession Planting Rosemary in Zone

4
successive plantings in Zone 's ~303-day season

Sow every 9.1 weeks for continuous harvest throughout the season.

Growing Tips for Rosemary in Zone

Zone has a short growing season (~303 days). Start Rosemary indoors early and use season-extension techniques like row covers and cold frames.

Grow in well-drained soil and avoid overwatering. In cold climates, grow in containers and bring indoors for winter. Propagate from stem cuttings for faster results than seed.

Companion Planting

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Saving Rosemary Seeds

Recommended for Your Garden

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Fabric Grow Bags $10-25

Breathable fabric pots that promote healthy root growth and prevent overwatering.

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Self-Watering Planters $15-40

Built-in reservoir keeps herbs and greens consistently watered with less effort.

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Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

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Frequently Asked Questions

When should I plant Rosemary in Zone 9a?

In Zone 9a, plan your Rosemary planting around the average last frost date of February 10. Transplant seedlings around February 17.

Can Rosemary grow in Zone 9a?

Yes, Rosemary can grow well in Zone 9a, hardy in USDA zones 7a through 10b. Zone 9a has a growing season of approximately 303 days, which is sufficient for Rosemary (80-180 days to maturity).

When can I harvest Rosemary in Zone 9a?

In Zone 9a, expect to harvest Rosemary from May 12 – September 29. Rosemary takes 80-180 days from planting to harvest.

What is the last frost date for Zone 9a?

The average last spring frost in Zone 9a is around February 10, and the first fall frost is around December 10. This gives a growing season of approximately 303 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Rosemary?

Good companion plants for Rosemary include Sage, Thyme, Lavender, Carrots. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Your Free Printable Garden Planner

A 24-page printable planner tailored to your zone. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.