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When to Plant Zucchini in Douglas County, MN

Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.

Douglas County, Minnesota is in USDA Zone 4a. The average last spring frost is May 3 and the first fall frost is October 4, giving you a growing season of approximately 154 days.

At an elevation of 1,010 feet, Douglas County receives approximately 37.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Zucchini to ensure they mature before fall.

Douglas County, MN (Zone 4a) Moderate season
154 days
Last Spring Frost May 3
154 growing days
First Fall Frost October 4

Douglas County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (29 days to spare)
Start indoors: Mar 15 Transplant: May 17 🍅 Harvest: Jul 5 – Aug 30
Recommended (50%) ✓ Fits season (28 days to spare)
Start indoors: Mar 22 Transplant: May 24 🍅 Harvest: Jul 12 – Sep 6
Safe Start (90%) ✓ Fits season (26 days to spare)
Start indoors: Apr 4 Transplant: Jun 6 🍅 Harvest: Jul 25 – Sep 19

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
Zucchini needs ~564 GDD — county provides 1,655 GDD Excellent fit

Zucchini Planting Timeline โ€” Douglas County, MN

Zucchini Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 โ€“ Apr 5
Transplant Outdoors May 24 May 24 โ€“ Jun 7
Direct Sow May 17 May 17 โ€“ Jun 7
Harvest July 12 Jul 12 โ€“ Sep 6

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

45โ€“60 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 4a

Growing Season

154 days

Growing Tips for Douglas County

Direct sow after last frost. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Zucchini in Douglas County, MN?

Douglas County is in Zone 4a with an average last frost of May 3. Plan your Zucchini planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Douglas County, MN?

Douglas County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 3 and first fall frost is October 4.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Douglas County gardeners in Zone 4a 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 Douglas County, MN. Local conditions may vary. Last updated: April 2026.