When to plant Thai Basil in McDonough County, IL
Thai Basil planted in McDonough County between April 24 and May 15 matures in 50–75 days — well before the October 17 first frost.
When to Plant Thai Basil in McDonough County, IL
What to do in June
A quick June briefing for McDonough County, Illinois gardeners — what's urgent, what's next, and what can wait.
Thai basil has a distinctive anise-licorice flavor with sturdy purple stems and small leaves. It is essential in Thai, Vietnamese, and other Southeast Asian cuisines.
McDonough County, Illinois is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 17, giving you a growing season of approximately 183 days.
At an elevation of 738 feet, McDonough County receives approximately 37.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Thai Basil to ensure they mature before fall.
McDonough County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.3
Drainage
Well Drained
Thai Basil 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 McDonough County
How your county's soil matches Thai Basil's growing requirements.
Soil pH
Your soil pH (6.2–7.3) overlaps with Thai Basil's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in McDonough County is excellent for Thai Basil — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Thai Basil.
Organic Matter
Organic matter is excellent (4.3%) — Thai Basil will thrive.
How to Plant Thai Basil
Succession Planting Thai Basil
Sow every 5.7 weeks. Last sowing by Aug 03 to harvest before frost.
Thai Basil Water Budget
Monthly Watering Guide for Thai Basil
Thai 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 | Thai Basil Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| May | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jul | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Sep | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Oct | 4.3" | 3.3" | 1" | 💧 Light watering |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in McDonough County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Thai Basil 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.
Thai Basil Planting Timeline — McDonough County, IL
Thai Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 27 | Feb 27 – Mar 13 |
| Transplant Outdoors | May 1 | May 1 – May 15 |
| Direct Sow | April 24 | Apr 24 – May 15 |
| Harvest | June 26 | Jun 26 – Aug 28 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | 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
1"/week · 1-2 times/week
📅 Days to Maturity
50–75 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
183 days in McDonough County
Growing Tips for Thai Basil in McDonough County
Direct sow Thai Basil outdoors after April 17 in McDonough County when soil has warmed and frost danger has passed.
General growing tips
Start seeds indoors or direct sow after last frost. Thai basil holds up better to heat in cooking than sweet basil. Pinch flowers to prolong leaf production.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Thai Basil in Other Locations
Frequently Asked Questions
When should I plant Thai Basil in McDonough County, IL?
McDonough County is in Zone 6a with an average last frost of April 17. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.
What planting zone is McDonough County, IL?
McDonough County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 17.
When should I plant Thai Basil in McDonough County, IL?
In McDonough County, IL, plant Thai Basil after the last frost (around April 17) and before the first frost (around October 17). Best results when soil holds above 50°F.
What growing zone is McDonough County, IL for Thai Basil?
McDonough County sits in USDA Zone 6a. Thai Basil grows reliably in zones 4a through 11b, so it's a good fit here.
Can Thai Basil grow in McDonough County's climate?
Yes — Thai Basil grows well in McDonough County's temperate climate. McDonough County averages a 183-day frost-free season, with last frost around April 17 and first frost around October 17.
Your McDonough County Garden Planner — Free
A 22-page printable planner built for McDonough County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.