When to plant Basil in Moline, IL
For Basil in Moline, the safe spring window opens around April 22 and closes around May 13. Last expected frost is April 15, first fall frost October 19, giving a 187-day growing season.
When to Plant Basil in Moline, IL
Top priorities for Rock Island County, Illinois gardeners in June
A quick June briefing for Rock Island County, Illinois gardeners — what's urgent, what's next, and what can wait.
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Begin indoor sowing: basil
You're about 16 weeks out from your last frost — the perfect window to get these germinating indoors.
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Basket week: basil
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
Looking ahead to 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.
Moline, Illinois is in USDA Zone 5b. The average last spring frost is April 15 and the first fall frost is October 19, giving you a growing season of approximately 187 days.
At an elevation of 1,172 feet, Rock Island County receives approximately 35.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Basil to ensure they mature before fall.
Moline Soil Profile
Soil Type
Silt Loam
Soil pH
6.3-6.9
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 Moline
How your county's soil matches Basil's growing requirements.
Soil pH
Your soil pH (6.3–6.9) is within Basil's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Rock Island County is excellent for Basil — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.7%) — Basil will thrive.
How to Plant Basil
Succession Planting Basil
Sow every 5.7 weeks. Last sowing by Aug 05 to harvest before frost.
Basil Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 2.6" | 3.6" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 3.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 4.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 2.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 2.8" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Rock Island 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 — Moline, IL
Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 25 | Feb 25 – Mar 11 |
| Transplant Outdoors | April 29 | Apr 29 – May 13 |
| Direct Sow | April 22 | Apr 22 – May 13 |
| Harvest | June 24 | Jun 24 – Aug 26 |
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 · Natural rainfall sufficient
📅 Days to Maturity
50–75 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
187 days in Rock Island County
Growing Tips for Basil in Moline
Direct sow Basil outdoors after April 15 in Rock Island 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 Moline, IL?
In Moline, IL, plant Basil after the last frost (around April 15) and before the first frost (around October 19). Best results when soil holds above 50°F.
What growing zone is Moline, IL for Basil?
Moline sits in USDA Zone 5b. Basil grows reliably in zones 4a through 11b, so it's a good fit here.
Can Basil grow in Moline's climate?
Yes — Basil grows well in Moline's temperate climate. Moline averages a 187-day frost-free season, with last frost around April 15 and first frost around October 19.
Your Rock Island County Garden Planner — Free
A 22-page printable planner built for Rock Island County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.