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When to Plant Pumpkin in Sublette County, WY

Sublette County, Wyoming Zone 4b May

Your May game plan for Sublette County, Wyoming

Here's what deserves your attention in Sublette County, Wyoming this month. Everything below is tailored to Zone 4b and timed around your local frost dates.

Avg. last frost June 22
Avg. first frost August 24
Soil temp (4") 36°F
Watering High
Pest pressure Low
Daylight 14.4 hrs

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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.

Sublette County, Wyoming is in USDA Zone 4b. The average last spring frost is June 22 and the first fall frost is August 24, giving you a growing season of approximately 63 days.

At an elevation of 5,005 feet, Sublette County receives approximately 22.8 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Pumpkin to ensure they mature before fall.

Sublette County, WY (Zone 4b) Very short season
63 days
Last Spring Frost June 22
63 growing days
First Fall Frost August 24

Sublette County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: May 6 Transplant: Jul 8 🍅 Harvest: Oct 7 – Nov 25
Recommended (50%) ✗ May not fit
Start indoors: May 11 Transplant: Jul 13 🍅 Harvest: Oct 12 – Nov 30
Safe Start (90%) ✗ May not fit
Start indoors: May 19 Transplant: Jul 21 🍅 Harvest: Oct 20 – Dec 8

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 Sublette County

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

Soil pH

Your soil pH (6.7–7.8) overlaps with Pumpkin's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Pumpkin.

How to Plant Pumpkin

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

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
1.5″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.8" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.6" 0" ❄️ Dormant
May 2.5" 0" ❄️ Dormant
Jun 5.6" 1.5" 4.1" 🚿 Regular watering
Jul 5.6" 2.2" 3.4" 🚿 Regular watering
Aug 5.6" 2.1" 3.5" 🚿 Regular watering
Sep 1.7" 0" ❄️ Dormant
Oct 2" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Aug in Sublette 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 677 GDD May not mature

Pumpkin Planting Timeline — Sublette County, WY

Pumpkin Planting Calendar

Activity When Date Range
Start Indoors May 11 May 11 – May 25
Transplant Outdoors July 13 Jul 13 – Jul 27
Direct Sow July 6 Jul 6 – Jul 27
Harvest October 12 Oct 12 – Nov 30

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.3"/week · Natural rainfall sufficient

📅 Days to Maturity

85–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

63 days in Sublette County

Growing Tips for Pumpkin in Sublette County

Direct sow Pumpkin outdoors after June 22 in Sublette County when soil has warmed and frost danger has passed.

Your 63.0-day growing season in Sublette County is tight for Pumpkin (85.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

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.

Sublette County receives only 23" of rain annually. Pumpkin needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Sublette County, WY?

Sublette County is in Zone 4b with an average last frost of June 22. Plan your Pumpkin planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sublette County, WY?

Sublette County, Wyoming is in USDA Hardiness Zone 4b. The average last spring frost is June 22 and first fall frost is August 24.

🌱

Your Sublette County Garden Planner — Free

A 24-page printable planner built for Sublette County (Zone 4b). 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 Sublette County, WY. 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.