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When to Plant Zucchini in Itasca County, MN

Itasca County, Minnesota Zone 4a May

May to-do list for Itasca County, Minnesota

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Itasca County, Minnesota.

Avg. last frost May 10
Avg. first frost October 1
Soil temp (4") 51°F
Watering Low
Pest pressure Low
Daylight 14.9 hrs
  1. Move zucchini from tray to bed

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

  2. Plant zucchini from seed, right in the garden

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

June prep starts now
  • Starting indoors: zucchini

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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.

Itasca County, Minnesota is in USDA Zone 4a. The average last spring frost is May 10 and the first fall frost is October 1, giving you a growing season of approximately 144 days.

At an elevation of 506 feet, Itasca County receives approximately 40.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Zucchini to ensure they mature before fall.

Itasca County, MN (Zone 4a) Short season
144 days
Last Spring Frost May 10
144 growing days
First Fall Frost October 1

Itasca County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (21 days to spare)
Start indoors: Mar 22 Transplant: May 24 🍅 Harvest: Jul 12 – Sep 6
Recommended (50%) ✓ Fits season (18 days to spare)
Start indoors: Mar 29 Transplant: May 31 🍅 Harvest: Jul 19 – Sep 13
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: Apr 15 Transplant: Jun 17 🍅 Harvest: Aug 5 – Sep 30

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.

Soil Compatibility in Itasca County

How your county's soil matches Zucchini's growing requirements.

Soil pH

Your soil pH (6.0–7.3) is within Zucchini's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Itasca County is excellent for Zucchini — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.2%) — Zucchini will thrive.

How to Plant Zucchini

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Zucchini

3
successive plantings in your 144-day season

Sow every 5.1 weeks. Last sowing by Aug 02 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
1.2″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 17 gal / 100 sq ft

Monthly Watering Guide for Zucchini

Zucchini needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Zucchini Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 3.5" 0" ❄️ Dormant
May 5.2" 5" 0.2" 💧 Light watering
Jun 5.2" 5.5" 0" ✅ Rainfall sufficient
Jul 5.2" 4.7" 0.5" 💧 Light watering
Aug 5.2" 4.4" 0.8" 💧 Light watering
Sep 5.2" 3.1" 2.1" 💧 Light watering
Oct 5.2" 3.1" 2.1" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

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

Zucchini Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Zucchini needs ~564 GDD — county provides 1,548 GDD Excellent fit

Zucchini Planting Timeline — Itasca County, MN

Zucchini Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 24 May 24 – Jun 14
Harvest July 19 Jul 19 – Sep 13

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · Only during dry spells

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 4a

📆 Growing Season

144 days in Itasca County

Growing Tips for Zucchini in Itasca County

Direct sow Zucchini outdoors after May 10 in Itasca County when soil has warmed and frost danger has passed.

Common pests for Zucchini in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zucchini in Itasca County, MN?

Itasca County is in Zone 4a with an average last frost of May 10. Plan your Zucchini planting based on this frost date — see the calendar above for exact timing.

What planting zone is Itasca County, MN?

Itasca County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 10 and first fall frost is October 1.

🌱

Your Itasca County Garden Planner — Free

A 24-page printable planner built for Itasca County (Zone 4a). 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 Itasca County, MN. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.