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When to Plant Lemon Thyme in St. Francois County, MO

Lemon thyme is a low-growing perennial herb with tiny, citrus-scented leaves. It combines the savory quality of thyme with a bright lemon flavor, excellent with fish and poultry.

St. Francois County, Missouri is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 21, giving you a growing season of approximately 188 days.

At an elevation of 808 feet, St. Francois County receives approximately 41 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Lemon Thyme during the growing season.

St. Francois County, MO (Zone 6b) Moderate season
188 days
Last Spring Frost April 16
188 growing days
First Fall Frost October 21

St. Francois County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Transplant: Apr 15 🍅 Harvest: Jun 24 – Aug 26
Recommended (50%) ✓ Fits season (48 days to spare)
Transplant: Apr 23 🍅 Harvest: Jul 2 – Sep 3
Safe Start (90%) ✓ Fits season (50 days to spare)
Transplant: May 6 🍅 Harvest: Jul 15 – Sep 16

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
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Lemon Thyme needs ~1,460 GDD — county provides 3,431 GDD Excellent fit

Lemon Thyme Planting Timeline โ€” St. Francois County, MO

Lemon Thyme Planting Calendar

Activity When Date Range
Transplant Outdoors April 23 Apr 23 โ€“ May 7
Harvest July 2 Jul 2 โ€“ Sep 3

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 Transplant Outdoors
June โ€”
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

70โ€“90 days

Soil pH

6 โ€“ 8

USDA Zone

Zone 6b

Growing Season

188 days

Growing Tips for St. Francois County

Start from cuttings or divisions. Plant in well-drained soil. Trim back after flowering. Use as a fragrant ground cover or edging plant along garden paths.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Lemon Thyme in St. Francois County, MO?

St. Francois County is in Zone 6b with an average last frost of April 16. Plan your Lemon Thyme planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is St. Francois County, MO?

St. Francois County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 21.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help St. Francois County gardeners in Zone 6b 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. Francois County, MO. Local conditions may vary. Last updated: April 2026.