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When to Plant Rosemary in St. Clair County, AL

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.

St. Clair County, Alabama is in USDA Zone 7b. The average last spring frost is March 27 and the first fall frost is November 1, giving you a growing season of approximately 219 days.

At an elevation of 211 feet, St. Clair County receives approximately 48.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 89ยฐF, providing good warmth for Rosemary during the growing season. Clay soil retains moisture well for Rosemary, but amend with compost to improve drainage and prevent root rot.

St. Clair County, AL (Zone 7b) Long season
219 days
Last Spring Frost March 27
219 growing days
First Fall Frost November 1

St. Clair County Soil Profile

Soil Type

Clay Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Mar 27 🍅 Harvest: Jun 19 – Nov 6
Recommended (50%) ✗ May not fit
Transplant: Apr 3 🍅 Harvest: Jun 26 – Nov 13
Safe Start (90%) ✗ May not fit
Transplant: Apr 22 🍅 Harvest: Jul 15 – Dec 2

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.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Rosemary needs ~2,178 GDD — county provides 3,668 GDD Excellent fit

Rosemary Planting Timeline โ€” St. Clair County, AL

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors April 3 Apr 3 โ€“ Apr 17
Harvest June 26 Jun 26 โ€“ Nov 13

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

80โ€“180 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 7b

Growing Season

219 days

Growing Tips for St. Clair County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Rosemary in St. Clair County, AL?

St. Clair County is in Zone 7b with an average last frost of March 27. Plan your Rosemary planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is St. Clair County, AL?

St. Clair County, Alabama is in USDA Hardiness Zone 7b. The average last spring frost is March 27 and first fall frost is November 1.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help St. Clair County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

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