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When to Plant Tomatillo in Grand Isle County, VT

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

Grand Isle County, Vermont is in USDA Zone 4b. The average last spring frost is May 6 and the first fall frost is October 10, giving you a growing season of approximately 157 days.

At an elevation of 1,011 feet, Grand Isle County receives approximately 38.6 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.

Grand Isle County, VT (Zone 4b) Moderate season
157 days
Last Spring Frost May 6
157 growing days
First Fall Frost October 10

Grand Isle County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (4 days to spare)
Start indoors: Feb 26 Transplant: May 21 🍅 Harvest: Jul 23 – Oct 1
Recommended (50%) ✓ Fits season (3 days to spare)
Start indoors: Mar 4 Transplant: May 27 🍅 Harvest: Jul 29 – Oct 7
Safe Start (90%) ✓ Fits season (5 days to spare)
Start indoors: Mar 15 Transplant: Jun 7 🍅 Harvest: Aug 9 – Oct 18

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
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Tomatillo needs ~942 GDD — county provides 2,041 GDD Excellent fit

Tomatillo Planting Timeline โ€” Grand Isle County, VT

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors March 4 Mar 4 โ€“ Mar 18
Transplant Outdoors May 27 May 27 โ€“ Jun 10
Direct Sow May 20 May 20 โ€“ Jun 10
Harvest July 29 Jul 29 โ€“ Oct 7

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 4b

Growing Season

157 days

Growing Tips for Grand Isle 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 Grand Isle County, VT?

Grand Isle County is in Zone 4b with an average last frost of May 6. Plan your Tomatillo planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Grand Isle County, VT?

Grand Isle County, Vermont is in USDA Hardiness Zone 4b. The average last spring frost is May 6 and first fall frost is October 10.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Grand Isle County gardeners in Zone 4b 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 Grand Isle County, VT. Local conditions may vary. Last updated: April 2026.