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When to plant Pumpkin in Keweenaw County, MI

Keweenaw County's short 135-day growing season means one Pumpkin planting between May 26 and June 16. No fall crop in Zone 5b.

When to Plant Pumpkin in Keweenaw County, MI

Pumpkin
Keweenaw County, Michigan Zone 5b June

Top priorities for Keweenaw County, Michigan gardeners in June

Here's what deserves your attention in Keweenaw County, Michigan this month. Everything below is tailored to Zone 5b and timed around your local frost dates.

Avg. last frost May 19
Avg. first frost October 1
Soil temp (4") 64°F
Watering Low
Pest pressure High
Daylight 15.7 hrs
  1. Set out pumpkin seedlings

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Time to start pumpkin inside

    You're about 15 weeks out from your last frost — the perfect window to get these germinating indoors.

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Pumpkins are large-fruited squash varieties grown for eating, decoration, and seed production. They require ample space and a long, warm growing season.

Keweenaw County, Michigan is in USDA Zone 5b. The average last spring frost is May 19 and the first fall frost is October 1, giving you a growing season of approximately 135 days.

At an elevation of 1,035 feet, Keweenaw County receives approximately 40.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Pumpkin to ensure they mature before fall.

Keweenaw County, MI (Zone 5b) Short season
135 days
Last Spring Frost May 19
135 growing days
First Fall Frost October 1

Keweenaw County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.9

Drainage

Well Drained

Pumpkin Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 10 Transplant: May 29 🍅 Harvest: Aug 28 – Oct 16
Recommended (50%) ✗ May not fit
Start indoors: Apr 14 Transplant: Jun 2 🍅 Harvest: Sep 1 – Oct 20
Safe Start (90%) ✗ May not fit
Start indoors: Apr 30 Transplant: Jun 18 🍅 Harvest: Sep 17 – Nov 5

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 Keweenaw County

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

Soil pH

Your soil pH (6.1–6.9) is within Pumpkin's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.0%) — Pumpkin will thrive.

How to Plant Pumpkin

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

Pumpkin Water Budget

Plant needs
1.3″/week
Rainfall provides
1.3″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 33 gal / 100 sq ft

Monthly Watering Guide for Pumpkin

Pumpkin needs approximately 1.3 inches of water per week (5.6" per month). Here's how your county's rainfall compares month by month.

Month Pumpkin Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 3.7" 0" ❄️ Dormant
May 5.6" 4.2" 1.4" 💧 Light watering
Jun 5.6" 4.9" 0.7" 💧 Light watering
Jul 5.6" 5" 0.6" 💧 Light watering
Aug 5.6" 4.7" 0.9" 💧 Light watering
Sep 5.6" 3.7" 1.9" 💧 Light watering
Oct 5.6" 3.2" 2.4" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

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

Pumpkin 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.

Pumpkin needs ~1,102 GDD — county provides 1,451 GDD Excellent fit

Pumpkin Planting Timeline — Keweenaw County, MI

Pumpkin Planting Calendar

Activity When Date Range
Start Indoors April 14 Apr 14 – Apr 28
Transplant Outdoors June 2 Jun 2 – Jun 16
Direct Sow May 26 May 26 – Jun 16
Harvest September 1 Sep 1 – Oct 20

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.3"/week · Only during dry spells

📅 Days to Maturity

85–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

135 days in Keweenaw County

Growing Tips for Pumpkin in Keweenaw County

Direct sow Pumpkin outdoors after May 19 in Keweenaw County when soil has warmed and frost danger has passed.

Common pests for Pumpkin 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 on mounds after last frost. Allow 6-10 feet between plants. Slip a board under developing fruit to prevent rot. Harvest when rind is hard and deep in color.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Pumpkin in Keweenaw County, MI?

Keweenaw County is in Zone 5b with an average last frost of May 19. Plan your Pumpkin planting based on this frost date — see the calendar above for exact timing.

What planting zone is Keweenaw County, MI?

Keweenaw County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is May 19 and first fall frost is October 1.

When should I plant Pumpkin in Keweenaw County, MI?

In Keweenaw County, MI, plant Pumpkin after the last frost (around May 19) and before the first frost (around October 1). Best results when soil holds above 50°F.

What growing zone is Keweenaw County, MI for Pumpkin?

Keweenaw County sits in USDA Zone 5b. Pumpkin grows reliably in zones 3a through 10b, so it's a good fit here.

Can Pumpkin grow in Keweenaw County's climate?

Yes — Pumpkin grows well in Keweenaw County's temperate climate. Keweenaw County averages a 135-day frost-free season, with last frost around May 19 and first frost around October 1.

🌱

Your Keweenaw County Garden Planner — Free

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

Sources & credits

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