When to Plant Thyme in Mason County, IL
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.
Mason County, Illinois is in USDA Zone 5b. The average last spring frost is April 15 and the first fall frost is October 14, giving you a growing season of approximately 182 days.
At an elevation of 768 feet, Mason County receives approximately 30.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Thyme during the growing season.
Mason County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-6.9
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
Thyme Planting Timeline — Mason County, IL
Thyme Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 22 | Apr 22 – May 6 |
| Harvest | July 1 | Jul 1 – Sep 2 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| 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 5b
Growing Season
182 days
Growing Tips for Mason 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
Thyme in Other Locations
Frequently Asked Questions
When should I plant Thyme in Mason County, IL?
Mason County is in Zone 5b with an average last frost of April 15. Plan your Thyme planting based on this frost date — see the calendar above for exact timing.
What planting zone is Mason County, IL?
Mason County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 15 and first fall frost is October 14.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Mason County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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