When to plant Thai Basil in Henry County County,
Plant Thai Basil in Henry County County after April 21; the prime window is April 28–May 19.
When to Plant Thai Basil in Henry County, IA
Your June game plan for Henry County, Iowa
Each item below is timed to Henry County, Iowa's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Start thai basil under lights
Label every cell. You will absolutely forget which is which otherwise.
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Pick thai basil
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
July will be here before you know it — start on
- First harvests: thai basil
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.
Henry County, Iowa is in USDA Zone 5b. The average last spring frost is April 21 and the first fall frost is October 14, giving you a growing season of approximately 176 days.
At an elevation of 879 feet, Henry County receives approximately 40.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Thai Basil during the growing season.
Henry County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-7.2
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 Henry County
How your county's soil matches Thai Basil's growing requirements.
Soil pH
Your soil pH (5.8–7.2) overlaps with Thai Basil's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Henry County is excellent for Thai Basil — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.1%) — Thai Basil will thrive.
How to Plant Thai Basil
Succession Planting Thai Basil
Sow every 5.7 weeks. Last sowing by Jul 31 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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 4" | 0.3" | 💧 Light watering |
| Oct | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Henry 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 — Henry County, IA
Thai Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 3 | Mar 3 – Mar 17 |
| Transplant Outdoors | May 5 | May 5 – May 19 |
| Direct Sow | April 28 | Apr 28 – May 19 |
| Harvest | June 30 | Jun 30 – Sep 1 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
50–75 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
176 days in Henry County
Growing Tips for Thai Basil in Henry County
Direct sow Thai Basil outdoors after April 21 in Henry 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 Henry County, IA?
Henry County is in Zone 5b with an average last frost of April 21. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.
What planting zone is Henry County, IA?
Henry County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 21 and first fall frost is October 14.
When should I plant Thai Basil in Henry County County, ?
In Henry County County, , plant Thai Basil after the last frost (around April 21) and before the first frost (around October 14). Best results when soil holds above 50°F.
What growing zone is Henry County County, for Thai Basil?
Henry County County sits in USDA Zone 5b. Thai Basil grows reliably in zones 4a through 11b, so it's a good fit here.
Can Thai Basil grow in Henry County County's climate?
Yes — Thai Basil grows well in Henry County County's temperate climate. Henry County County averages a 176-day frost-free season, with last frost around April 21 and first frost around October 14.
Your Henry County Garden Planner — Free
A 22-page printable planner built for Henry 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.