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When to Plant Thyme in Addison County, VT

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.

Addison County, Vermont is in USDA Zone 4b. The average last spring frost is May 14 and the first fall frost is October 2, giving you a growing season of approximately 141 days.

At an elevation of 1,052 feet, Addison County receives approximately 46.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Thyme to ensure they mature before fall.

Addison County, VT (Zone 4b) Short season
141 days
Last Spring Frost May 14
141 growing days
First Fall Frost October 2

Addison County Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 16 🍅 Harvest: Jul 25 – Sep 26
Recommended (50%) ✓ Fits season (1 days to spare)
Transplant: May 21 🍅 Harvest: Jul 30 – Oct 1
Safe Start (90%) ✗ May not fit
Transplant: Jun 9 🍅 Harvest: Aug 18 – Oct 20

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
1.4″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Thyme needs ~800 GDD — county provides 1,410 GDD Excellent fit

Thyme Planting Timeline โ€” Addison County, VT

Thyme Planting Calendar

Activity When Date Range
Transplant Outdoors May 21 May 21 โ€“ Jun 4
Harvest July 30 Jul 30 โ€“ Oct 1

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

70โ€“90 days

Soil pH

6 โ€“ 8

USDA Zone

Zone 4b

Growing Season

141 days

Growing Tips for Addison County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Thyme in Addison County, VT?

Addison County is in Zone 4b with an average last frost of May 14. Plan your Thyme planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Addison County, VT?

Addison County, Vermont is in USDA Hardiness Zone 4b. The average last spring frost is May 14 and first fall frost is October 2.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Addison County gardeners in Zone 4b 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 Addison County, VT. Local conditions may vary. Last updated: April 2026.