When to plant Oregano in Williamson County, IL
Williamson County's short 193-day growing season means one Oregano planting between April 17 and May 1. No fall crop in Zone 7a.
When to Plant Oregano in Williamson County, IL
Top priorities for Williamson County, Illinois gardeners in June
Here's what deserves your attention in Williamson County, Illinois this month. Everything below is tailored to Zone 7a and timed around your local frost dates.
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Basket week: oregano
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
Get ahead of July
- First harvests: oregano
Oregano is a robust perennial herb essential to Italian and Greek cuisine. Its pungent, savory leaves intensify in flavor when dried.
Williamson County, Illinois is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 20, giving you a growing season of approximately 193 days.
At an elevation of 1,253 feet, Williamson County receives approximately 38.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Oregano during the growing season.
Williamson County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.2
Drainage
Well Drained
Oregano 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.
Soil Compatibility in Williamson County
How your county's soil matches Oregano's growing requirements.
Soil pH
Your soil pH (6.2–7.2) is within Oregano's preferred range (6.0–8.0).
Soil Texture
The silt loam soil in Williamson County is excellent for Oregano — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.4%) — Oregano will thrive.
How to Plant Oregano
Succession Planting Oregano
Sow every 6.9 weeks. Last sowing by Jul 22 to harvest before frost.
Oregano Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Oregano
Oregano needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.
| Month | Oregano Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 1.3" | 4" | 0" | ✅ Rainfall sufficient |
| May | 1.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 1.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 1.3" | 3.7" | 0" | ✅ Rainfall sufficient |
| Sep | 1.3" | 3.2" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 2.9" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 2.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Williamson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Oregano Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Oregano Planting Timeline — Williamson County, IL
Oregano Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 17 | Apr 17 – May 1 |
| Harvest | June 19 | Jun 19 – Aug 28 |
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 | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.3"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–8 · Your soil: ideal
🗺️ USDA Zone
Zone 7a
📆 Growing Season
193 days in Williamson County
Growing Tips for Oregano in Williamson County
Direct sow Oregano outdoors after April 10 in Williamson County when soil has warmed and frost danger has passed.
General growing tips
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
Check more plant combinations with our Companion Planting Checker →
Oregano in Other Locations
Frequently Asked Questions
When should I plant Oregano in Williamson County, IL?
Williamson County is in Zone 7a with an average last frost of April 10. Plan your Oregano planting based on this frost date — see the calendar above for exact timing.
What planting zone is Williamson County, IL?
Williamson County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 20.
When should I plant Oregano in Williamson County, IL?
In Williamson County, IL, plant Oregano after the last frost (around April 10) and before the first frost (around October 20). Best results when soil holds above 50°F.
What growing zone is Williamson County, IL for Oregano?
Williamson County sits in USDA Zone 7a. Oregano grows reliably in zones 4a through 10b, so it's a good fit here.
Can Oregano grow in Williamson County's climate?
Yes — Oregano grows well in Williamson County's temperate climate. Williamson County averages a 193-day frost-free season, with last frost around April 10 and first frost around October 20.
Your Williamson County Garden Planner — Free
A 22-page printable planner built for Williamson County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.