When to Plant Basil in Portage 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.
Portage County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 5 and the first fall frost is October 6, giving you a growing season of approximately 154 days.
At an elevation of 1,008 feet, Portage County receives approximately 37.6 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.
Portage County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Basil Planting Timeline — Portage County, WI
Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 10 | Mar 10 – Mar 24 |
| Transplant Outdoors | May 26 | May 26 – Jun 9 |
| Direct Sow | May 12 | May 12 – Jun 2 |
| Harvest | July 21 | Jul 21 – Sep 22 |
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
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 4b
📆 Growing Season
154 days in Portage County
Growing Tips for Portage 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
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 Portage County, WI?
Portage County is in Zone 4b with an average last frost of May 5. Plan your Basil planting based on this frost date — see the calendar above for exact timing.
What planting zone is Portage County, WI?
Portage County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 5 and first fall frost is October 6.
Your Portage County Garden Planner — Free
A 22-page printable planner built for Portage County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.