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When to Plant Tomatillo in Calumet County, WI

Tomatillos are a Mexican staple that produces tart, green fruits enclosed in papery husks. They are essential for salsa verde and green sauces.

Calumet County, Wisconsin is in USDA Zone 4b. The average last spring frost is April 30 and the first fall frost is October 12, giving you a growing season of approximately 165 days.

At an elevation of 767 feet, Calumet County receives approximately 38.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Tomatillo to ensure they mature before fall.

Calumet County, WI (Zone 4b) Moderate season
165 days
Last Spring Frost April 30
165 growing days
First Fall Frost October 12

Calumet County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (9 days to spare)
Start indoors: Feb 21 Transplant: May 16 🍅 Harvest: Jul 18 – Sep 26
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Feb 26 Transplant: May 21 🍅 Harvest: Jul 23 – Oct 1
Safe Start (90%) ✓ Fits season (11 days to spare)
Start indoors: Mar 13 Transplant: Jun 5 🍅 Harvest: Aug 7 – Oct 16

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

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 41 gal / 100 sq ft
Tomatillo needs ~834 GDD — county provides 1,897 GDD Excellent fit

Tomatillo Planting Timeline โ€” Calumet County, WI

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 โ€“ Mar 12
Transplant Outdoors May 21 May 21 โ€“ Jun 4
Direct Sow May 14 May 14 โ€“ Jun 4
Harvest July 23 Jul 23 โ€“ Oct 1

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April โ€”
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Harvest
August Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“85 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4b

Growing Season

165 days

Growing Tips for Calumet County

Start seeds indoors 6-8 weeks before last frost. Plant at least two plants for cross-pollination. Harvest when fruits fill the husk and it begins to split.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Dill

Level Up Your Garden

Frequently Asked Questions

When should I plant Tomatillo in Calumet County, WI?

Calumet County is in Zone 4b with an average last frost of April 30. Plan your Tomatillo planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Calumet County, WI?

Calumet County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is April 30 and first fall frost is October 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Calumet County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Calumet County, WI. Local conditions may vary. Last updated: April 2026.