When to Plant Basil in Winnebago County, IA
May to-do list for Winnebago County, Iowa
May is a pivotal month for Winnebago County, Iowa gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Harden off and plant basil
Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.
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Outdoor sowing time: basil
Mark the row. Birds and stray feet both have opinions about unmarked beds.
A few tasks this May that'll pay off in June
- Starting indoors: 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.
Winnebago County, Iowa is in USDA Zone 5a. The average last spring frost is April 28 and the first fall frost is October 6, giving you a growing season of approximately 161 days.
At an elevation of 520 feet, Winnebago County receives approximately 32.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Basil to ensure they mature before fall.
Winnebago County Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.9
Drainage
Well Drained
Plant 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 Winnebago County
How your county's soil matches Basil's growing requirements.
Soil pH
Your soil pH (6.0–6.9) is within Basil's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Winnebago County is excellent for Basil — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.1%) — Basil will thrive.
How to Plant Basil
Succession Planting Basil
Sow every 5.7 weeks. Last sowing by Jul 23 to harvest before frost.
Plant 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 | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | 2.6" | 3" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 3.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 3.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 3.4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 2.8" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 2.8" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Winnebago 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 — Winnebago County, IA
Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 10 | Mar 10 – Mar 24 |
| Transplant Outdoors | May 12 | May 12 – May 26 |
| Direct Sow | May 5 | May 5 – May 26 |
| Harvest | July 7 | Jul 7 – Sep 8 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| 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 5a
📆 Growing Season
161 days in Winnebago County
Growing Tips for Basil in Winnebago County
Direct sow Basil outdoors after April 28 in Winnebago 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
Frequently Asked Questions
When should I plant Basil in Winnebago County, IA?
Winnebago County is in Zone 5a with an average last frost of April 28. Plan your Basil planting based on this frost date — see the calendar above for exact timing.
What planting zone is Winnebago County, IA?
Winnebago County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 28 and first fall frost is October 6.
Your Winnebago County Garden Planner — Free
A 24-page printable planner built for Winnebago County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.