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When to Plant Hubbard Squash in Eagle County, CO

Hubbard squash is a large, bumpy-skinned winter squash with dense, sweet, dry flesh ideal for baking and pies. The hard shell allows storage for 6 months or more.

Eagle County, Colorado is in USDA Zone 4b. The average last spring frost is June 16 and the first fall frost is September 7, giving you a growing season of approximately 83 days.

At an elevation of 7,116 feet, Eagle County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Hubbard Squash to ensure they mature before fall.

Eagle County, CO (Zone 4b) Very short season
83 days
Last Spring Frost June 16
83 growing days
First Fall Frost September 7

Eagle County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 24 Transplant: Jun 26 🍅 Harvest: Oct 9 – Nov 13
Recommended (50%) ✗ May not fit
Start indoors: May 5 Transplant: Jul 7 🍅 Harvest: Oct 20 – Nov 24
Safe Start (90%) ✗ May not fit
Start indoors: May 16 Transplant: Jul 18 🍅 Harvest: Oct 31 – Dec 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 Eagle County

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

Soil pH

Your soil pH (6.6โ€“7.7) is more alkaline than Hubbard Squash prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

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

How to Plant Hubbard Squash

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

Plant Water Budget

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

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Hubbard Squash

Hubbard Squash needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Hubbard Squash Needs Rainfall You Supplement Action
Jan โ€” 1.8" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 2.4" 0" โ„๏ธ Dormant
Apr โ€” 2.8" 0" โ„๏ธ Dormant
May โ€” 3.2" 0" โ„๏ธ Dormant
Jun 4.3" 1.6" 2.7" ๐Ÿšฟ Regular watering
Jul 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Aug 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Sep 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Oct โ€” 2" 0" โ„๏ธ Dormant
Nov โ€” 1.6" 0" โ„๏ธ Dormant
Dec โ€” 1.5" 0" โ„๏ธ Dormant

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

Hubbard 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.

Hubbard Squash needs ~1,182 GDD — county provides 892 GDD May not mature

Hubbard Squash Planting Timeline โ€” Eagle County, CO

Hubbard Squash Planting Calendar

Activity When Date Range
Start Indoors May 5 May 5 โ€“ May 19
Transplant Outdoors July 7 Jul 7 โ€“ Jul 21
Direct Sow June 30 Jun 30 โ€“ Jul 21
Harvest October 20 Oct 20 โ€“ Nov 24

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

100โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

83 days in Eagle County

Growing Tips for Hubbard Squash in Eagle County

Direct sow Hubbard Squash outdoors after June 16 in Eagle County when soil has warmed and frost danger has passed.

Your 83.0-day growing season in Eagle County is tight for Hubbard Squash (100.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Eagle County receives only 24" of rain annually. Hubbard Squash needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors in short-season areas. Requires ample space and rich soil. Harvest when the skin is very hard and the color is deep. Cure in the sun before storing.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hubbard Squash in Eagle County, CO?

Eagle County is in Zone 4b with an average last frost of June 16. Plan your Hubbard Squash planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Eagle County, CO?

Eagle County, Colorado is in USDA Hardiness Zone 4b. The average last spring frost is June 16 and first fall frost is September 7.

๐ŸŒฑ

Plan Your Garden with Confidence

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