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When to Plant Sunchoke in Luce 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.

Luce County, Michigan is in USDA Zone 4b. The average last spring frost is May 22 and the first fall frost is October 3, giving you a growing season of approximately 134 days.

At an elevation of 1,157 feet, Luce County receives approximately 36.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Sunchoke to ensure they mature before fall.

Luce County, MI (Zone 4b) Short season
134 days
Last Spring Frost May 22
134 growing days
First Fall Frost October 3

Luce County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 29 🍅 Harvest: Sep 18 – Oct 23
Recommended (50%) ✗ May not fit
Transplant: Jun 5 🍅 Harvest: Sep 25 – Oct 30
Safe Start (90%) ✗ May not fit
Transplant: Jun 22 🍅 Harvest: Oct 12 – Nov 16

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
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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

Sunchoke needs ~1,690 GDD — county provides 1,742 GDD Good fit

Sunchoke Planting Timeline โ€” Luce County, MI

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors June 5 Jun 5 โ€“ Jun 19
Harvest September 25 Sep 25 โ€“ Oct 30

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May โ€”
June Transplant Outdoors
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 4b

Growing Season

134 days

Growing Tips for Luce 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 Luce County, MI?

Luce County is in Zone 4b with an average last frost of May 22. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Luce County, MI?

Luce County, Michigan is in USDA Hardiness Zone 4b. The average last spring frost is May 22 and first fall frost is October 3.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Luce County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

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Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Luce County, MI. Local conditions may vary. Last updated: April 2026.