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When to Plant Crosne in Ontonagon County, MI

Crosne (Chinese artichoke) produces small, segmented white tubers with a crunchy texture and mild artichoke-nutty flavor. They are a rare delicacy in French cuisine.

Ontonagon County, Michigan is in USDA Zone 4a. The average last spring frost is May 22 and the first fall frost is September 28, giving you a growing season of approximately 129 days.

At an elevation of 502 feet, Ontonagon County receives approximately 42 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Crosne to ensure they mature before fall.

Ontonagon County, MI (Zone 4a) Short season
129 days
Last Spring Frost May 22
129 growing days
First Fall Frost September 28

Ontonagon County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 18 🍅 Harvest: Oct 19 – Oct 12
Recommended (50%) ✗ May not fit
Transplant: May 22 🍅 Harvest: Oct 23 – Oct 16
Safe Start (90%) ✗ May not fit
Transplant: Jun 6 🍅 Harvest: Nov 7 – Oct 31

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
1.4″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Crosne needs ~1,750 GDD — county provides 1,290 GDD May not mature

Crosne Planting Timeline โ€” Ontonagon County, MI

Crosne Planting Calendar

Activity When Date Range
Direct Sow May 15 May 15 โ€“ Jun 5
Fall Sowing July 6 Jul 6 โ€“ Jul 20
Harvest October 16 Oct 16 โ€“ Oct 9

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Direct Sow
June Direct Sow
July Fall Sowing
August โ€”
September โ€”
October Harvest
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

150โ€“200 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4a

Growing Season

129 days

Growing Tips for Ontonagon County

Plant tubers 3 inches deep in spring. Mark the location well as plants die back. Harvest in late fall after frost. Leave some tubers in ground for next year. Very labor-intensive to harvest.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Crosne in Ontonagon County, MI?

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

What planting zone is Ontonagon County, MI?

Ontonagon County, Michigan is in USDA Hardiness Zone 4a. The average last spring frost is May 22 and first fall frost is September 28.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Ontonagon County gardeners in Zone 4a 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 Ontonagon County, MI. Local conditions may vary. Last updated: April 2026.