When to Plant Oregano in Marshall County, IL
Oregano is a robust perennial herb essential to Italian and Greek cuisine. Its pungent, savory leaves intensify in flavor when dried.
Marshall County, Illinois is in USDA Zone 5a. The average last spring frost is April 21 and the first fall frost is October 13, giving you a growing season of approximately 175 days.
At an elevation of 1,177 feet, Marshall County receives approximately 30.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Oregano to ensure they mature before fall.
Marshall County Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.8
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
Oregano Planting Timeline — Marshall County, IL
Oregano Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 28 | Apr 28 – May 12 |
| Harvest | June 30 | Jun 30 – Sep 8 |
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 | Harvest |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Low — drought tolerant
Days to Maturity
60–90 days
Soil pH
6 – 8
USDA Zone
Zone 5a
Growing Season
175 days
Growing Tips for Marshall County
Start from seed, cuttings, or divisions. Harvest just before flowering for strongest flavor. Cut plants back to a few inches in spring to encourage vigorous new growth.
Companion Planting
Good Companions
Level Up Your Garden
Oregano in Other Locations
Frequently Asked Questions
When should I plant Oregano in Marshall County, IL?
Marshall County is in Zone 5a with an average last frost of April 21. Plan your Oregano planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marshall County, IL?
Marshall County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 21 and first fall frost is October 13.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Marshall County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
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