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When to Plant Sunchoke in Shiawassee County, MI

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

Shiawassee County, Michigan is in USDA Zone 5b. The average last spring frost is April 29 and the first fall frost is October 14, giving you a growing season of approximately 168 days.

At an elevation of 803 feet, Shiawassee County receives approximately 30.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Sunchoke during the growing season.

Shiawassee County, MI (Zone 5b) Moderate season
168 days
Last Spring Frost April 29
168 growing days
First Fall Frost October 14

Shiawassee County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 10 🍅 Harvest: Aug 30 – Oct 25
Recommended (50%) ✗ May not fit
Transplant: May 13 🍅 Harvest: Sep 2 – Oct 28
Safe Start (90%) ✗ May not fit
Transplant: May 29 🍅 Harvest: Sep 18 – Nov 13

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
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 344 gal / 100 sq ft
Sunchoke needs ~1,982 GDD — county provides 2,562 GDD Good fit

Sunchoke Planting Timeline โ€” Shiawassee County, MI

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors May 13 May 13 โ€“ May 27
Harvest September 2 Sep 2 โ€“ Oct 28

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 โ€”
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 5b

Growing Season

168 days

Growing Tips for Shiawassee 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 Shiawassee County, MI?

Shiawassee County is in Zone 5b with an average last frost of April 29. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Shiawassee County, MI?

Shiawassee County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is April 29 and first fall frost is October 14.

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Plan Your Garden with Confidence

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