When to plant Basil in Ohlman, IL
Ohlman gardeners should plant Basil between April 20 and May 11 in spring. With Ohlman's Zone 6b climate (last frost April 13), Basil needs 50–75 days to mature — plant by August 7 for a full harvest.
When to Plant Basil in Ohlman, IL
Top priorities for Montgomery County, Illinois gardeners in June
If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.
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Fire up the seed-starting tray: basil
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
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It's harvest week for basil
If you can't use it all right away, check the food-preservation section of your planner.
Get ahead of July
- First harvests: basil
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.
Ohlman, Illinois is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 21, giving you a growing season of approximately 191 days.
At an elevation of 1,331 feet, Montgomery County receives approximately 30.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Basil during the growing season.
Ohlman Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-7.2
Drainage
Well Drained
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 Ohlman
How your county's soil matches Basil's growing requirements.
Soil pH
Your soil pH (6.1–7.2) overlaps with Basil's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Montgomery County is excellent for Basil — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Basil.
Organic Matter
Organic matter is excellent (5.2%) — Basil will thrive.
How to Plant Basil
Succession Planting Basil
Sow every 5.7 weeks. Last sowing by Aug 07 to harvest before frost.
Basil Water Budget
Monthly Watering Guide for Basil
Basil needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.
| Month | Basil Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | 2.6" | 2.6" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 3.7" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 3.1" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 3.1" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 2.4" | 0.2" | 💧 Light watering |
| Nov | — | 2.1" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Montgomery County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
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.
Basil Planting Timeline — Ohlman, IL
Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 23 | Feb 23 – Mar 9 |
| Transplant Outdoors | April 27 | Apr 27 – May 11 |
| Direct Sow | April 20 | Apr 20 – May 11 |
| Harvest | June 22 | Jun 22 – Aug 24 |
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
0.6"/week · Only during dry spells
📅 Days to Maturity
50–75 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
191 days in Montgomery County
Growing Tips for Basil in Ohlman
Direct sow Basil outdoors after April 13 in Montgomery County when soil has warmed and frost danger has passed.
General growing tips
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
When should I plant Basil in Ohlman, IL?
In Ohlman, IL, plant Basil after the last frost (around April 13) and before the first frost (around October 21). Best results when soil holds above 50°F.
What growing zone is Ohlman, IL for Basil?
Ohlman sits in USDA Zone 6b. Basil grows reliably in zones 4a through 11b, so it's a good fit here.
Can Basil grow in Ohlman's climate?
Yes — Basil grows well in Ohlman's temperate climate. Ohlman averages a 191-day frost-free season, with last frost around April 13 and first frost around October 21.
Your Montgomery County Garden Planner — Free
A 22-page printable planner built for Montgomery County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.