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When to plant Tomatillo in Flathead County, MT

Flathead County's short 99-day growing season means one Tomatillo planting between June 10 and July 1. No fall crop in Zone 5a.

When to Plant Tomatillo in Flathead County, MT

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

Flathead County, Montana is in USDA Zone 5a. The average last spring frost is June 3 and the first fall frost is September 10, giving you a growing season of approximately 99 days.

At an elevation of 6,233 feet, Flathead County receives approximately 20.7 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Tomatillo during the growing season.

Flathead County, MT (Zone 5a) Very short season
99 days
Last Spring Frost June 3
99 growing days
First Fall Frost September 10

Flathead County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Tomatillo Planting Timeline — Flathead County, MT

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 – Apr 22
Transplant Outdoors June 17 Jun 17 – Jul 1
Direct Sow June 10 Jun 10 – Jul 1
Harvest August 19 Aug 19 – Oct 28

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May
June Transplant Outdoors Direct Sow
July Transplant Outdoors Direct Sow
August Harvest
September Harvest
October Harvest
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 5a

📆 Growing Season

99 days in Flathead County

Growing Tips for Flathead 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 Flathead County, MT?

Flathead County is in Zone 5a with an average last frost of June 3. Plan your Tomatillo planting based on this frost date — see the calendar above for exact timing.

What planting zone is Flathead County, MT?

Flathead County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is June 3 and first fall frost is September 10.

When should I plant Tomatillo in Flathead County, MT?

In Flathead County, MT, plant Tomatillo after the last frost (around June 3) and before the first frost (around September 10). Best results when soil holds above 50°F.

What growing zone is Flathead County, MT for Tomatillo?

Flathead County sits in USDA Zone 5a. Tomatillo grows reliably in zones 4a through 11b, so it's a good fit here.

Can Tomatillo grow in Flathead County's climate?

Yes — Tomatillo grows well in Flathead County's temperate climate. Flathead County averages a 99-day frost-free season, with last frost around June 3 and first frost around September 10.

🌱

Your Flathead County Garden Planner — Free

A 22-page printable planner built for Flathead County (Zone 5a). 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 Flathead County, MT. Local conditions may vary. Last updated: June 2026.

Sources & credits

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