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When to Plant Butternut Squash in Garfield County, UT

Butternut squash is a popular winter squash with a long neck, small seed cavity, and sweet, nutty orange flesh. It stores exceptionally well for months.

Garfield County, Utah is in USDA Zone 5b. The average last spring frost is May 27 and the first fall frost is September 21, giving you a growing season of approximately 117 days.

At an elevation of 5,058 feet, Garfield County receives approximately 20.3 inches of rainfall annually with predominantly loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Butternut Squash to ensure they mature before fall.

Garfield County, UT (Zone 5b) Short season
117 days
Last Spring Frost May 27
117 growing days
First Fall Frost September 21

Garfield County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 10 Transplant: May 29 🍅 Harvest: Aug 28 – Oct 2
Recommended (50%) ✗ May not fit
Start indoors: Apr 22 Transplant: Jun 10 🍅 Harvest: Sep 9 – Oct 14
Safe Start (90%) ✗ May not fit
Start indoors: May 20 Transplant: Jul 8 🍅 Harvest: Oct 7 – Nov 11

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 Garfield County

How your county's soil matches Butternut Squash's growing requirements.

Soil pH

Your soil pH (6.5โ€“7.7) is more alkaline than Butternut Squash prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Garfield County is excellent for Butternut Squash โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Butternut Squash

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

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.7″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 464 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Butternut Squash

Butternut Squash needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Butternut Squash Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.3" 0" โ„๏ธ Dormant
Mar โ€” 1.9" 0" โ„๏ธ Dormant
Apr โ€” 2.1" 0" โ„๏ธ Dormant
May 4.8" 2.3" 2.5" ๐Ÿšฟ Regular watering
Jun 4.8" 1.4" 3.4" ๐Ÿšฟ Regular watering
Jul 4.8" 1.6" 3.2" ๐Ÿšฟ Regular watering
Aug 4.8" 2" 2.8" ๐Ÿšฟ Regular watering
Sep 4.8" 1.8" 3" ๐Ÿšฟ Regular watering
Oct โ€” 2" 0" โ„๏ธ Dormant
Nov โ€” 1.5" 0" โ„๏ธ Dormant
Dec โ€” 1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Garfield County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Butternut Squash 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" โ€” every day above 50ยฐF 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.

Butternut Squash needs ~1,268 GDD — county provides 1,521 GDD Good fit

Butternut Squash Planting Timeline โ€” Garfield County, UT

Butternut Squash Planting Calendar

Activity When Date Range
Start Indoors April 22 Apr 22 โ€“ May 6
Transplant Outdoors June 10 Jun 10 โ€“ Jun 24
Direct Sow June 3 Jun 3 โ€“ Jun 24
Harvest September 9 Sep 9 โ€“ Oct 14

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

85โ€“110 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

117 days in Garfield County

Growing Tips for Butternut Squash in Garfield County

Direct sow Butternut Squash outdoors after May 27 in Garfield County when soil has warmed and frost danger has passed.

Your 117.0-day growing season in Garfield County is tight for Butternut Squash (85.0-110.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Garfield County receives only 20" of rain annually. Butternut Squash needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 3 weeks early or direct sow after frost. Allow 6-8 feet for sprawling vines. Harvest when the skin is hard and uniformly tan. Cure in the sun for 10 days.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Butternut Squash in Garfield County, UT?

Garfield County is in Zone 5b with an average last frost of May 27. Plan your Butternut Squash planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Garfield County, UT?

Garfield County, Utah is in USDA Hardiness Zone 5b. The average last spring frost is May 27 and first fall frost is September 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Garfield County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Garfield County, UT. Local conditions may vary. Last updated: April 2026.