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When to Plant Spaghetti Squash in Henry County, IA

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

Henry County, Iowa is in USDA Zone 5b. The average last spring frost is April 21 and the first fall frost is October 14, giving you a growing season of approximately 176 days.

At an elevation of 879 feet, Henry County receives approximately 40.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Spaghetti Squash during the growing season.

Henry County, IA (Zone 5b) Moderate season
176 days
Last Spring Frost April 21
176 growing days
First Fall Frost October 14

Henry County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (45 days to spare)
Start indoors: Mar 10 Transplant: Apr 28 🍅 Harvest: Jul 28 – Aug 25
Recommended (50%) ✓ Fits season (43 days to spare)
Start indoors: Mar 17 Transplant: May 5 🍅 Harvest: Aug 4 – Sep 1
Safe Start (90%) ✓ Fits season (44 days to spare)
Start indoors: Mar 30 Transplant: May 18 🍅 Harvest: Aug 17 – Sep 14

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
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 64 gal / 100 sq ft
Spaghetti Squash needs ~1,341 GDD — county provides 2,552 GDD Excellent fit

Spaghetti Squash Planting Timeline โ€” Henry County, IA

Spaghetti Squash Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 โ€“ Mar 31
Transplant Outdoors May 5 May 5 โ€“ May 19
Direct Sow April 28 Apr 28 โ€“ May 19
Harvest August 4 Aug 4 โ€“ Sep 1

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Direct Sow
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 5b

Growing Season

176 days

Growing Tips for Henry 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Spaghetti Squash in Henry County, IA?

Henry County is in Zone 5b with an average last frost of April 21. Plan your Spaghetti Squash planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Henry County, IA?

Henry County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 21 and first fall frost is October 14.

๐ŸŒฑ

Plan Your Garden with Confidence

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