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When to Plant Sunchoke in Monona County, IA

Sunchokes (Jerusalem artichokes) are a native sunflower relative grown for their knobby, nutty-flavored tubers. They are extremely productive and nearly impossible to eradicate.

Monona County, Iowa is in USDA Zone 5a. The average last spring frost is April 26 and the first fall frost is October 10, giving you a growing season of approximately 167 days.

At an elevation of 732 feet, Monona County receives approximately 35.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Sunchoke to ensure they mature before fall.

Monona County, IA (Zone 5a) Moderate season
167 days
Last Spring Frost April 26
167 growing days
First Fall Frost October 10

Monona County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 5 🍅 Harvest: Aug 25 – Oct 20
Recommended (50%) ✗ May not fit
Transplant: May 10 🍅 Harvest: Aug 30 – Oct 25
Safe Start (90%) ✗ May not fit
Transplant: May 25 🍅 Harvest: Sep 14 – Nov 9

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
0.9″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 744 gal / 100 sq ft
Drought risk

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

Sunchoke needs ~1,592 GDD — county provides 2,045 GDD Good fit

Sunchoke Planting Timeline โ€” Monona County, IA

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors May 10 May 10 โ€“ May 24
Harvest August 30 Aug 30 โ€“ Oct 25

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

110โ€“150 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 5a

Growing Season

167 days

Growing Tips for Monona County

Plant tubers 4 inches deep in early spring. Contain plants with barriers as they spread aggressively. Harvest after frost or leave in ground and dig as needed through winter.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Sunchoke in Monona County, IA?

Monona County is in Zone 5a with an average last frost of April 26. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Monona County, IA?

Monona County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 26 and first fall frost is October 10.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Monona 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 Monona County, IA. Local conditions may vary. Last updated: April 2026.