When to Plant Basil in Grant County, WI
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.
Grant County, Wisconsin is in USDA Zone 4b. The average last spring frost is April 28 and the first fall frost is October 8, giving you a growing season of approximately 163 days.
At an elevation of 884 feet, Grant County receives approximately 37.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Basil to ensure they mature before fall.
Grant County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-7.1
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
Basil Planting Timeline — Grant County, WI
Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 3 | Mar 3 – Mar 17 |
| Transplant Outdoors | May 19 | May 19 – Jun 2 |
| Direct Sow | May 5 | May 5 – May 26 |
| Harvest | July 14 | Jul 14 – Sep 15 |
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 |
| 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
163 days
Growing Tips for Grant County
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
Level Up Your Garden
Isolate 150 ft between varieties. Different basil species can cross.
Basil in Other Locations
Frequently Asked Questions
When should I plant Basil in Grant County, WI?
Grant County is in Zone 4b 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 Grant County, WI?
Grant County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is April 28 and first fall frost is October 8.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Grant County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.
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