When to Plant Lemon Thyme in Clarke County, IA
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.
Clarke County, Iowa is in USDA Zone 5a. The average last spring frost is April 24 and the first fall frost is October 11, giving you a growing season of approximately 170 days.
At an elevation of 1,182 feet, Clarke County receives approximately 35.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Lemon Thyme during the growing season.
Clarke County Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.9
Drainage
Well Drained
Plant Planting Risk Windows
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
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Lemon Thyme Planting Timeline — Clarke County, IA
Lemon Thyme Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 1 | May 1 – May 15 |
| Harvest | July 10 | Jul 10 – Sep 11 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Low — drought tolerant
Days to Maturity
70–90 days
Soil pH
6 – 8
USDA Zone
Zone 5a
Growing Season
170 days
Growing Tips for Clarke 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
Lemon Thyme in Other Locations
Frequently Asked Questions
When should I plant Lemon Thyme in Clarke County, IA?
Clarke County is in Zone 5a with an average last frost of April 24. Plan your Lemon Thyme planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clarke County, IA?
Clarke County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 24 and first fall frost is October 11.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Clarke County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
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