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When to Plant Rosemary in Glynn County, GA

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.

Glynn County, Georgia is in USDA Zone 9a. The average last spring frost is February 9 and the first fall frost is December 13, giving you a growing season of approximately 307 days.

At an elevation of 135 feet, Glynn County receives approximately 55.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 97ยฐF, so Rosemary may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Rosemary will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Rosemary root diseases.

Glynn County, GA (Zone 9a) Year-round
307 days
Last Spring Frost February 9
307 growing days
First Fall Frost December 13

Glynn County Soil Profile

Soil Type

Sandy Loam

Soil pH

4.9-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (81 days to spare)
Transplant: Feb 3 🍅 Harvest: Apr 28 – Sep 15
Recommended (50%) ✓ Fits season (76 days to spare)
Transplant: Feb 16 🍅 Harvest: May 11 – Sep 28
Safe Start (90%) ✓ Fits season (60 days to spare)
Transplant: Mar 16 🍅 Harvest: Jun 8 – Oct 26

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
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Rosemary needs ~2,958 GDD — county provides 7,007 GDD Excellent fit

Rosemary Planting Timeline โ€” Glynn County, GA

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors February 16 Feb 16 โ€“ Mar 2
Harvest May 11 May 11 โ€“ Sep 28

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Transplant Outdoors
March Transplant Outdoors
April โ€”
May Harvest
June Harvest
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
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 9a

Growing Season

307 days

Growing Tips for Glynn 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 Glynn County, GA?

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

What planting zone is Glynn County, GA?

Glynn County, Georgia is in USDA Hardiness Zone 9a. The average last spring frost is February 9 and first fall frost is December 13.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Glynn County gardeners in Zone 9a 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 Glynn County, GA. Local conditions may vary. Last updated: April 2026.