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When to Plant Rosemary in USDA Zone 9b

Zone 9b Zone 9b April

Top priorities for Zone 9b gardeners in April

We've pulled the most time-sensitive tasks for Zone 9b this April and put them front and centre. Tackle them in order.

Avg. last frost February 2
Avg. first frost December 18
Before May arrives, get these ready
  • First harvests: rosemary
Get the full Zone 9b 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 9b, the average last spring frost is around January 25 and the first fall frost is around December 20, giving you a growing season of approximately 329 days.

Zone 9b Year-round
329 days
Last Spring Frost January 25
329 growing days
First Fall Frost December 20

Rosemary Planting Timeline — Zone 9b

Where Is USDA Zone 9b?

The map below highlights the states that contain Zone 9b. 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 9b

Activity When Date Range
Transplant Outdoors February 1 Feb 1 – Feb 15
Harvest April 26 Apr 26 – Sep 13

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

Month-by-Month Timeline

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

Free Zone 9b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 9b 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

329 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 ~329-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 (~329 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

🪴
Fabric Grow Bags $10-25

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

🏺
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.

Related Plants

Frequently Asked Questions

When should I plant Rosemary in Zone 9b?

In Zone 9b, plan your Rosemary planting around the average last frost date of January 25. Transplant seedlings around February 1.

Can Rosemary grow in Zone 9b?

Yes, Rosemary can grow well in Zone 9b, hardy in USDA zones 7a through 10b. Zone 9b has a growing season of approximately 329 days, which is sufficient for Rosemary (80-180 days to maturity).

When can I harvest Rosemary in Zone 9b?

In Zone 9b, expect to harvest Rosemary from April 26 – September 13. Rosemary takes 80-180 days from planting to harvest.

What is the last frost date for Zone 9b?

The average last spring frost in Zone 9b is around January 25, and the first fall frost is around December 20. This gives a growing season of approximately 329 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.