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When to Plant Tomatillo in Vilas 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.

Vilas County, Wisconsin is in USDA Zone 4a. The average last spring frost is May 21 and the first fall frost is September 29, giving you a growing season of approximately 131 days.

At an elevation of 543 feet, Vilas County receives approximately 36.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Tomatillo to ensure they mature before fall.

Vilas County, WI (Zone 4a) Short season
131 days
Last Spring Frost May 21
131 growing days
First Fall Frost September 29

Vilas County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 15 Transplant: Jun 7 🍅 Harvest: Aug 9 – Oct 18
Recommended (50%) ✗ May not fit
Start indoors: Mar 19 Transplant: Jun 11 🍅 Harvest: Aug 13 – Oct 22
Safe Start (90%) ✗ May not fit
Start indoors: Mar 31 Transplant: Jun 23 🍅 Harvest: Aug 25 – Nov 3

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.

Soil Compatibility in Vilas County

How your county's soil matches Tomatillo's growing requirements.

Soil pH

Your soil pH (5.8โ€“7.3) overlaps with Tomatillo's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Vilas County is excellent for Tomatillo โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.0%) โ€” Tomatillo will thrive.

How to Plant Tomatillo

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Tomatillo

2
successive plantings in your 131-day season

Sow every 6.9 weeks. Last sowing by Jul 06 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Tomatillo

Tomatillo needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Tomatillo Needs Rainfall You Supplement Action
Jan โ€” 1.3" 0" โ„๏ธ Dormant
Feb โ€” 1.7" 0" โ„๏ธ Dormant
Mar โ€” 2.6" 0" โ„๏ธ Dormant
Apr โ€” 3.6" 0" โ„๏ธ Dormant
May 4.8" 4.3" 0.5" ๐Ÿ’ง Light watering
Jun 4.8" 4.3" 0.5" ๐Ÿ’ง Light watering
Jul 4.8" 4.2" 0.6" ๐Ÿ’ง Light watering
Aug 4.8" 4.4" 0.4" ๐Ÿ’ง Light watering
Sep 4.8" 2.9" 1.9" ๐Ÿ’ง Light watering
Oct โ€” 2.9" 0" โ„๏ธ Dormant
Nov โ€” 2.2" 0" โ„๏ธ Dormant
Dec โ€” 2.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Vilas County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Tomatillo Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Tomatillo needs ~942 GDD — county provides 1,703 GDD Excellent fit

Tomatillo Planting Timeline โ€” Vilas County, WI

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 โ€“ Apr 2
Transplant Outdoors June 11 Jun 11 โ€“ Jun 25
Direct Sow June 4 Jun 4 โ€“ Jun 25
Harvest August 13 Aug 13 โ€“ Oct 22

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“85 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

131 days in Vilas County

Growing Tips for Tomatillo in Vilas County

Direct sow Tomatillo outdoors after May 21 in Vilas County when soil has warmed and frost danger has passed.

Common pests for Tomatillo in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Tomatillo in Vilas County, WI?

Vilas County is in Zone 4a with an average last frost of May 21. Plan your Tomatillo planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Vilas County, WI?

Vilas County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is May 21 and first fall frost is September 29.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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