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When to Plant Tomatillo in Itasca County, MN

Itasca County, Minnesota Zone 4a May

May in the garden — Itasca County, Minnesota

Welcome to May in Zone 4a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 10
Avg. first frost October 1
Soil temp (4") 51°F
Watering Low
Pest pressure Low
Daylight 14.9 hrs
  1. Set out tomatillo seedlings

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Plant tomatillo from seed, right in the garden

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

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

Itasca County, Minnesota is in USDA Zone 4a. The average last spring frost is May 10 and the first fall frost is October 1, giving you a growing season of approximately 144 days.

At an elevation of 506 feet, Itasca County receives approximately 40.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Tomatillo to ensure they mature before fall.

Itasca County, MN (Zone 4a) Short season
144 days
Last Spring Frost May 10
144 growing days
First Fall Frost October 1

Itasca County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 1 Transplant: May 24 🍅 Harvest: Jul 26 – Oct 4
Recommended (50%) ✗ May not fit
Start indoors: Mar 8 Transplant: May 31 🍅 Harvest: Aug 2 – Oct 11
Safe Start (90%) ✗ May not fit
Start indoors: Mar 25 Transplant: Jun 17 🍅 Harvest: Aug 19 – Oct 28

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 Itasca County

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

Soil pH

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

Soil Texture

The silt loam soil in Itasca County is excellent for Tomatillo — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.2%) — Tomatillo will thrive.

How to Plant Tomatillo

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

Succession Planting Tomatillo

2
successive plantings in your 144-day season

Sow every 6.9 weeks. Last sowing by Jul 08 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 1.7" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 3.5" 0" ❄️ Dormant
May 4.8" 5" 0" ✅ Rainfall sufficient
Jun 4.8" 5.5" 0" ✅ Rainfall sufficient
Jul 4.8" 4.7" 0.1" 💧 Light watering
Aug 4.8" 4.4" 0.4" 💧 Light watering
Sep 4.8" 3.1" 1.7" 💧 Light watering
Oct 4.8" 3.1" 1.7" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Itasca County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~779 GDD — county provides 1,548 GDD Excellent fit

Tomatillo Planting Timeline — Itasca County, MN

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors March 8 Mar 8 – Mar 22
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 24 May 24 – Jun 14
Harvest August 2 Aug 2 – Oct 11

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · Natural rainfall sufficient

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

144 days in Itasca County

Growing Tips for Tomatillo in Itasca County

Direct sow Tomatillo outdoors after May 10 in Itasca 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 Itasca County, MN?

Itasca County is in Zone 4a with an average last frost of May 10. Plan your Tomatillo planting based on this frost date — see the calendar above for exact timing.

What planting zone is Itasca County, MN?

Itasca County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 10 and first fall frost is October 1.

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Your Itasca County Garden Planner — Free

A 24-page printable planner built for Itasca County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Itasca County, MN. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.