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When to plant Tomatillo in St. Clair County, MI

Plant Tomatillo in St. Clair County after April 27; the prime window is May 4–May 25.

When to Plant Tomatillo in St. Clair County, MI

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

St. Clair County, Michigan is in USDA Zone 6a. The average last spring frost is April 27 and the first fall frost is October 27, giving you a growing season of approximately 183 days.

At an elevation of 1,065 feet, St. Clair County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Tomatillo during the growing season.

St. Clair County, MI (Zone 6a) Moderate season
183 days
Last Spring Frost April 27
183 growing days
First Fall Frost October 27

St. Clair County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.2

Drainage

Well Drained

Monthly Watering Guide for Tomatillo

Tomatillo needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Tomatillo Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in St. Clair County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Tomatillo Planting Timeline — St. Clair County, MI

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 – Mar 16
Transplant Outdoors May 11 May 11 – May 25
Direct Sow May 4 May 4 – May 25
Harvest July 13 Jul 13 – Sep 21

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
July Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

183 days in St. Clair County

Growing Tips for St. Clair 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Tomatillo in St. Clair County, MI?

St. Clair County is in Zone 6a with an average last frost of April 27. Plan your Tomatillo planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Clair County, MI?

St. Clair County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 27 and first fall frost is October 27.

When should I plant Tomatillo in St. Clair County, MI?

In St. Clair County, MI, plant Tomatillo after the last frost (around April 27) and before the first frost (around October 27). Best results when soil holds above 50°F.

What growing zone is St. Clair County, MI for Tomatillo?

St. Clair County sits in USDA Zone 6a. Tomatillo grows reliably in zones 4a through 11b, so it's a good fit here.

Can Tomatillo grow in St. Clair County's climate?

Yes — Tomatillo grows well in St. Clair County's temperate climate. St. Clair County averages a 183-day frost-free season, with last frost around April 27 and first frost around October 27.

🌱

Your St. Clair County Garden Planner — Free

A 22-page printable planner built for St. Clair County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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