When to Plant Thai Basil in Adams County, WI
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.
Adams County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 6 and the first fall frost is October 5, giving you a growing season of approximately 152 days.
At an elevation of 1,055 feet, Adams County receives approximately 41.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Thai Basil to ensure they mature before fall.
Adams County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.9
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.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Thai Basil Planting Timeline — Adams County, WI
Thai Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 11 | Mar 11 – Mar 25 |
| Transplant Outdoors | May 27 | May 27 – Jun 10 |
| Direct Sow | May 13 | May 13 – Jun 3 |
| Harvest | July 22 | Jul 22 – Sep 23 |
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 | 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
6 – 7
USDA Zone
Zone 4b
Growing Season
152 days
Growing Tips for Adams 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
Level Up Your Garden
Thai Basil in Other Locations
Frequently Asked Questions
When should I plant Thai Basil in Adams County, WI?
Adams County is in Zone 4b with an average last frost of May 6. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.
What planting zone is Adams County, WI?
Adams County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 6 and first fall frost is October 5.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Adams County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.
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