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When to Plant Spaghetti Squash in Weld County, CO

Spaghetti squash is a winter squash whose cooked flesh separates into pasta-like strands. It is a popular low-carb alternative to pasta.

Weld County, Colorado is in USDA Zone 5a. The average last spring frost is May 2 and the first fall frost is October 7, giving you a growing season of approximately 158 days.

At an elevation of 6,992 feet, Weld County receives approximately 18.8 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Spaghetti Squash during the growing season. With low rainfall, drip irrigation is essential for growing Spaghetti Squash successfully. Mulch heavily to conserve soil moisture.

Weld County, CO (Zone 5a) Moderate season
158 days
Last Spring Frost May 2
158 growing days
First Fall Frost October 7

Weld County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (25 days to spare)
Start indoors: Mar 23 Transplant: May 11 🍅 Harvest: Aug 10 – Sep 7
Recommended (50%) ✓ Fits season (25 days to spare)
Start indoors: Mar 28 Transplant: May 16 🍅 Harvest: Aug 15 – Sep 12
Safe Start (90%) ✓ Fits season (20 days to spare)
Start indoors: Apr 14 Transplant: Jun 2 🍅 Harvest: Sep 1 – Sep 29

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 844 gal / 100 sq ft
Drought risk

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

Spaghetti Squash needs ~1,411 GDD — county provides 2,409 GDD Excellent fit

Spaghetti Squash Planting Timeline โ€” Weld County, CO

Spaghetti Squash Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 โ€“ Apr 11
Transplant Outdoors May 16 May 16 โ€“ May 30
Direct Sow May 9 May 9 โ€“ May 30
Harvest August 15 Aug 15 โ€“ Sep 12

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

85โ€“100 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5a

Growing Season

158 days

Growing Tips for Weld County

Direct sow on mounds after last frost. Harvest when skin turns golden yellow and is hard. Store in a cool, dry place for 2-3 months. Bake or microwave halves until tender.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

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Frequently Asked Questions

When should I plant Spaghetti Squash in Weld County, CO?

Weld County is in Zone 5a with an average last frost of May 2. Plan your Spaghetti Squash planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Weld County, CO?

Weld County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 2 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Weld County gardeners in Zone 5a 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 Weld County, CO. Local conditions may vary. Last updated: April 2026.