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When to Plant Thyme in Guilford County, NC

Guilford County, North Carolina Zone 8a May

May in Guilford County, North Carolina — your action list

Welcome to May in Zone 8a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 6
Avg. first frost October 30
Soil temp (4") 70°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
June will be here before you know it — start on
  • First harvests: thyme

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Thyme is a low-growing perennial herb with tiny, aromatic leaves and a warm, earthy flavor. It is one of the most versatile culinary and medicinal herbs.

Guilford County, North Carolina is in USDA Zone 8a. The average last spring frost is April 6 and the first fall frost is October 30, giving you a growing season of approximately 207 days.

At an elevation of 579 feet, Guilford County receives approximately 45.6 inches of rainfall annually with predominantly clay loam soil. Summer highs average 90°F, providing good warmth for Thyme during the growing season. Clay soil retains moisture well for Thyme, but amend with compost to improve drainage and prevent root rot.

Guilford County, NC (Zone 8a) Long season
207 days
Last Spring Frost April 6
207 growing days
First Fall Frost October 30
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Guilford County Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (70 days to spare)
Transplant: Apr 3 🍅 Harvest: Jun 12 – Aug 14
Recommended (50%) ✓ Fits season (67 days to spare)
Transplant: Apr 13 🍅 Harvest: Jun 22 – Aug 24
Safe Start (90%) ✓ Fits season (65 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 9 – Sep 10

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 Guilford County

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

Soil pH

Your soil pH (5.6–6.4) overlaps with Thyme's range (6.0–8.0), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Thyme

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

Succession Planting Thyme

3
successive plantings in your 207-day season

Sow every 8 weeks. Last sowing by Aug 01 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Thyme

Thyme 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 Thyme Needs Rainfall You Supplement Action
Jan 4" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 4.4" 0" ❄️ Dormant
Apr 1.3" 3" 0" ✅ Rainfall sufficient
May 1.3" 4" 0" ✅ Rainfall sufficient
Jun 1.3" 4.2" 0" ✅ Rainfall sufficient
Jul 1.3" 4.6" 0" ✅ Rainfall sufficient
Aug 1.3" 3.9" 0" ✅ Rainfall sufficient
Sep 1.3" 3.4" 0" ✅ Rainfall sufficient
Oct 1.3" 3.2" 0" ✅ Rainfall sufficient
Nov 3.3" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Guilford County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Thyme 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.

Thyme needs ~1,400 GDD — county provides 3,622 GDD Excellent fit

Thyme Planting Timeline — Guilford County, NC

Thyme Planting Calendar

Activity When Date Range
Transplant Outdoors April 13 Apr 13 – Apr 27
Harvest June 22 Jun 22 – Aug 24

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Natural rainfall sufficient

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–8 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

207 days in Guilford County

Growing Tips for Thyme in Guilford County

Direct sow Thyme outdoors after April 06 in Guilford County when soil has warmed and frost danger has passed.

With Guilford County's clay soil (32% clay), work in 3-4 inches of compost before planting Thyme. Avoid tilling when soil is wet to prevent compaction.

General growing tips

Start from seed, cuttings, or divisions. Plant in well-drained, lean soil. Prune lightly after flowering. Replace plants every 3-4 years when they become woody.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Thyme in Guilford County, NC?

Guilford County is in Zone 8a with an average last frost of April 6. Plan your Thyme planting based on this frost date — see the calendar above for exact timing.

What planting zone is Guilford County, NC?

Guilford County, North Carolina is in USDA Hardiness Zone 8a. The average last spring frost is April 6 and first fall frost is October 30.

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Your Guilford County Garden Planner — Free

A 24-page printable planner built for Guilford 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.

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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 Guilford 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.