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When to Plant Tomatillo in Gem County, ID

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

Gem County, Idaho is in USDA Zone 6a. The average last spring frost is May 9 and the first fall frost is October 1, giving you a growing season of approximately 145 days.

At an elevation of 6,100 feet, Gem County receives approximately 16 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Tomatillo during the growing season. With low rainfall, drip irrigation is essential for growing Tomatillo successfully. Mulch heavily to conserve soil moisture.

Gem County, ID (Zone 6a) Short season
145 days
Last Spring Frost May 9
145 growing days
First Fall Frost October 1

Gem County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 6 Transplant: May 15 🍅 Harvest: Jul 17 – Sep 25
Recommended (50%) ✗ May not fit
Start indoors: Mar 14 Transplant: May 23 🍅 Harvest: Jul 25 – Oct 3
Safe Start (90%) ✗ May not fit
Start indoors: Apr 12 Transplant: Jun 21 🍅 Harvest: Aug 23 – Nov 1

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
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 831 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Tomatillo needs ~1,106 GDD — county provides 2,211 GDD Excellent fit

Tomatillo Planting Timeline โ€” Gem County, ID

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 โ€“ Mar 28
Transplant Outdoors May 23 May 23 โ€“ Jun 6
Direct Sow May 16 May 16 โ€“ Jun 6
Harvest July 25 Jul 25 โ€“ Oct 3

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
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 6a

Growing Season

145 days

Growing Tips for Gem 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 Gem County, ID?

Gem County is in Zone 6a with an average last frost of May 9. Plan your Tomatillo planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Gem County, ID?

Gem County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 9 and first fall frost is October 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Gem County gardeners in Zone 6a 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 Gem County, ID. Local conditions may vary. Last updated: April 2026.