When to Plant Basil in Monroe County, IL
Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.
Monroe County, Illinois is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 24, giving you a growing season of approximately 193 days.
At an elevation of 1,278 feet, Monroe County receives approximately 34.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Basil during the growing season.
Monroe County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.8
Drainage
Well Drained
Monthly Watering Guide for Basil
Basil needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Basil Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.2" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| May | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jun | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jul | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Aug | 4.3" | 4" | 0.3" | 💧 Light watering |
| Sep | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Oct | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Monroe County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Basil Planting Timeline — Monroe County, IL
Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 24 | Feb 24 – Mar 10 |
| Transplant Outdoors | April 28 | Apr 28 – May 12 |
| Direct Sow | April 21 | Apr 21 – May 12 |
| Harvest | June 23 | Jun 23 – Aug 25 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
50–75 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
193 days in Monroe County
Growing Tips for Monroe County
Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 150 ft between varieties. Different basil species can cross.
Basil in Other Locations
Frequently Asked Questions
When should I plant Basil in Monroe County, IL?
Monroe County is in Zone 6b with an average last frost of April 14. Plan your Basil planting based on this frost date — see the calendar above for exact timing.
What planting zone is Monroe County, IL?
Monroe County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 24.
Plan Your Garden with Confidence
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