Blog

When to Plant Sunchoke in Alger 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.

Alger County, Michigan is in USDA Zone 4b. The average last spring frost is May 10 and the first fall frost is October 16, giving you a growing season of approximately 159 days.

At an elevation of 1,014 feet, Alger County receives approximately 40.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Sunchoke to ensure they mature before fall.

Alger County, MI (Zone 4b) Moderate season
159 days
Last Spring Frost May 10
159 growing days
First Fall Frost October 16

Alger County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 16 🍅 Harvest: Sep 5 – Oct 10
Recommended (50%) ✗ May not fit
Transplant: May 24 🍅 Harvest: Sep 13 – Oct 18
Safe Start (90%) ✓ Fits season (0 days to spare)
Transplant: Jun 8 🍅 Harvest: Sep 28 – Nov 2

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
1.1″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 311 gal / 100 sq ft
Sunchoke needs ~1,300 GDD — county provides 1,590 GDD Good fit

Sunchoke Planting Timeline โ€” Alger County, MI

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors May 24 May 24 โ€“ Jun 7
Harvest September 13 Sep 13 โ€“ Oct 18

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 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

159 days

Growing Tips for Alger 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 Alger County, MI?

Alger County is in Zone 4b with an average last frost of May 10. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Alger County, MI?

Alger County, Michigan is in USDA Hardiness Zone 4b. The average last spring frost is May 10 and first fall frost is October 16.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

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 Alger County, MI. Local conditions may vary. Last updated: April 2026.