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When to plant Butternut Squash in Jackson County, CO

Jackson County's short 83-day growing season means one Butternut Squash planting between June 27 and July 18. No fall crop in Zone 4b.

When to Plant Butternut Squash in Jackson County, CO

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.

Jackson County, Colorado is in USDA Zone 4b. The average last spring frost is June 13 and the first fall frost is September 4, giving you a growing season of approximately 83 days.

At an elevation of 5,388 feet, Jackson County receives approximately 20.9 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Butternut Squash to ensure they mature before fall.

Jackson County, CO (Zone 4b) Very short season
83 days
Last Spring Frost June 13
83 growing days
First Fall Frost September 4

Jackson County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Butternut Squash Planting Timeline — Jackson County, CO

Butternut Squash Planting Calendar

Activity When Date Range
Start Indoors May 2 May 2 – May 16
Transplant Outdoors July 4 Jul 4 – Jul 18
Direct Sow June 27 Jun 27 – Jul 18
Harvest October 3 Oct 3 – Nov 7

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

85–110 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 4b

📆 Growing Season

83 days in Jackson County

Growing Tips for Jackson County

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 Jackson County, CO?

Jackson County is in Zone 4b with an average last frost of June 13. Plan your Butternut Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jackson County, CO?

Jackson County, Colorado is in USDA Hardiness Zone 4b. The average last spring frost is June 13 and first fall frost is September 4.

When should I plant Butternut Squash in Jackson County, CO?

In Jackson County, CO, plant Butternut Squash after the last frost (around June 13) and before the first frost (around September 4). Best results when soil holds above 50°F.

What growing zone is Jackson County, CO for Butternut Squash?

Jackson County sits in USDA Zone 4b. Butternut Squash grows reliably in zones 3a through 11b, so it's a good fit here.

Can Butternut Squash grow in Jackson County's climate?

Yes — Butternut Squash grows well in Jackson County's temperate climate. Jackson County averages a 83-day frost-free season, with last frost around June 13 and first frost around September 4.

🌱

Your Jackson County Garden Planner — Free

A 22-page printable planner built for Jackson 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 Jackson County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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