Blog

When to Plant Rosemary in Forsyth County, NC

Forsyth County, North Carolina Zone 8a May

This month in Forsyth County, North Carolina

A quick May briefing for Forsyth County, North Carolina gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 11
Avg. first frost October 22
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs

Instant PDF download. No spam, unsubscribe any time.

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.

Forsyth County, North Carolina is in USDA Zone 8a. The average last spring frost is April 11 and the first fall frost is October 22, giving you a growing season of approximately 194 days.

At an elevation of 424 feet, Forsyth County receives approximately 44.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 90°F, 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.

Forsyth County, NC (Zone 8a) Moderate season
194 days
Last Spring Frost April 11
194 growing days
First Fall Frost October 22

Forsyth County Soil Profile

Soil Type

Clay Loam

Soil pH

5.7-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 14 🍅 Harvest: Jul 7 – Nov 24
Recommended (50%) ✗ May not fit
Transplant: Apr 18 🍅 Harvest: Jul 11 – Nov 28
Safe Start (90%) ✗ May not fit
Transplant: May 8 🍅 Harvest: Jul 31 – Dec 18

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 Forsyth County

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

Soil pH

Your soil pH (5.7–6.3) overlaps with Rosemary's range (6.0–7.5), though not a perfect match.

Soil Texture

The clay loam soil in Forsyth County is excellent for Rosemary — good drainage, moisture retention, and nutrient holding capacity.

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

2
successive plantings in your 194-day season

Sow every 9.1 weeks. Last sowing by Apr 25 to harvest before frost.

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 4.1" 0" ❄️ Dormant
Feb 3.5" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 1.3" 3.1" 0" ✅ Rainfall sufficient
May 1.3" 3.8" 0" ✅ Rainfall sufficient
Jun 1.3" 4.2" 0" ✅ Rainfall sufficient
Jul 1.3" 4.5" 0" ✅ Rainfall sufficient
Aug 1.3" 4.1" 0" ✅ Rainfall sufficient
Sep 1.3" 3.1" 0" ✅ Rainfall sufficient
Oct 1.3" 3" 0" ✅ Rainfall sufficient
Nov 3.7" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Forsyth County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~2,275 GDD — county provides 3,395 GDD Excellent fit

Rosemary Planting Timeline — Forsyth County, NC

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors April 18 Apr 18 – May 2
Harvest July 11 Jul 11 – Nov 28

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Natural rainfall sufficient

📅 Days to Maturity

80–180 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

194 days in Forsyth County

Growing Tips for Rosemary in Forsyth County

Direct sow Rosemary outdoors after April 11 in Forsyth County when soil has warmed and frost danger has passed.

With Forsyth County's clay soil (29% clay), work in 3-4 inches of compost before planting Rosemary. Avoid tilling when soil is wet to prevent compaction.

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 Forsyth County, NC?

Forsyth County is in Zone 8a with an average last frost of April 11. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.

What planting zone is Forsyth County, NC?

Forsyth County, North Carolina is in USDA Hardiness Zone 8a. The average last spring frost is April 11 and first fall frost is October 22.

🌱

Your Forsyth County Garden Planner — Free

A 24-page printable planner built for Forsyth County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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