When to Plant Thai Basil in Ottawa County, MI
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.
Ottawa County, Michigan is in USDA Zone 5b. The average last spring frost is May 9 and the first fall frost is October 9, giving you a growing season of approximately 153 days.
At an elevation of 1,027 feet, Ottawa County receives approximately 41.9 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.
Ottawa County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.8
Drainage
Well Drained
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.6" | 0" | ❄️ Dormant |
| Apr | — | 4.1" | 0" | ❄️ Dormant |
| May | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.8" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Oct | 4.3" | 3" | 1.3" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Ottawa County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Thai Basil Planting Timeline — Ottawa County, MI
Thai Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 21 | Mar 21 – Apr 4 |
| Transplant Outdoors | May 23 | May 23 – Jun 6 |
| Direct Sow | May 16 | May 16 – Jun 6 |
| Harvest | July 18 | Jul 18 – Sep 19 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
50–75 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 5b
📆 Growing Season
153 days in Ottawa County
Growing Tips for Ottawa County
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 Ottawa County, MI?
Ottawa County is in Zone 5b with an average last frost of May 9. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.
What planting zone is Ottawa County, MI?
Ottawa County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is May 9 and first fall frost is October 9.
Plan Your Garden with Confidence
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