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When to Plant Rosemary in Sutter County, CA

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.

Sutter County, California is in USDA Zone 9a. The average last spring frost is March 4 and the first fall frost is November 26, giving you a growing season of approximately 267 days.

At an elevation of 484 feet, Sutter County receives approximately 21.4 inches of rainfall annually with predominantly loam soil. Summer highs average 88ยฐF, providing good warmth for Rosemary during the growing season.

Sutter County, CA (Zone 9a) Long season
267 days
Last Spring Frost March 4
267 growing days
First Fall Frost November 26

Sutter County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Transplant: Feb 14 🍅 Harvest: May 9 – Sep 26
Recommended (50%) ✓ Fits season (36 days to spare)
Transplant: Mar 11 🍅 Harvest: Jun 3 – Oct 21
Safe Start (90%) ✓ Fits season (3 days to spare)
Transplant: May 4 🍅 Harvest: Jul 27 – Dec 14

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Sutter County

How your county's soil matches Rosemary's growing requirements.

Soil pH

Your soil pH (6.8โ€“7.7) overlaps with Rosemary's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in Sutter County is excellent for Rosemary โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Rosemary.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Rosemary.

How to Plant Rosemary

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Rosemary

3
successive plantings in your 267-day season

Sow every 9.1 weeks. Last sowing by May 30 to harvest before frost.

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
0.3″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 152 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Rosemary

Rosemary needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Rosemary Needs Rainfall You Supplement Action
Jan โ€” 4.6" 0" โ„๏ธ Dormant
Feb โ€” 4.2" 0" โ„๏ธ Dormant
Mar 1.3" 3.7" 0" โœ… Rainfall sufficient
Apr 1.3" 1.4" 0" โœ… Rainfall sufficient
May 1.3" 0.6" 0.7" ๐Ÿšฟ Regular watering
Jun 1.3" 0.1" 1.2" ๐Ÿšฟ Regular watering
Jul 1.3" 0" 1.3" ๐Ÿšฟ Regular watering
Aug 1.3" 0" 1.3" ๐Ÿšฟ Regular watering
Sep 1.3" 0.2" 1.1" ๐Ÿšฟ Regular watering
Oct 1.3" 0.9" 0.4" ๐Ÿ’ง Light watering
Nov 1.3" 1.8" 0" โœ… Rainfall sufficient
Dec โ€” 3.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Sutter County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Rosemary Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Rosemary needs ~2,080 GDD — county provides 4,272 GDD Excellent fit

Rosemary Planting Timeline โ€” Sutter County, CA

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors March 11 Mar 11 โ€“ Mar 25
Harvest June 3 Jun 3 โ€“ Oct 21

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.3"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

80โ€“180 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

267 days in Sutter County

Growing Tips for Rosemary in Sutter County

Direct sow Rosemary outdoors after March 04 in Sutter County when soil has warmed and frost danger has passed.

General growing tips

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

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rosemary in Sutter County, CA?

Sutter County is in Zone 9a with an average last frost of March 4. Plan your Rosemary planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sutter County, CA?

Sutter County, California is in USDA Hardiness Zone 9a. The average last spring frost is March 4 and first fall frost is November 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sutter County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Sutter County, CA. Local conditions may vary. Last updated: April 2026.