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When to Plant Asparagus in Oneida County, WI

Asparagus is a long-lived perennial vegetable that produces tender spears each spring for 15-20 years once established. It requires patience but rewards with reliable harvests.

Oneida County, Wisconsin is in USDA Zone 4a. The average last spring frost is May 20 and the first fall frost is September 28, giving you a growing season of approximately 131 days.

At an elevation of 569 feet, Oneida County receives approximately 39.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Asparagus to ensure they mature before fall.

Oneida County, WI (Zone 4a) Short season
131 days
Last Spring Frost May 20
131 growing days
First Fall Frost September 28

Oneida County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 29
Recommended (50%) ✓ Fits season
Transplant: Jun 3
Safe Start (90%) ✓ Fits season
Transplant: Jun 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
1.3″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Asparagus needs ~10,494 GDD — county provides 1,506 GDD May not mature

Asparagus Planting Timeline โ€” Oneida County, WI

Asparagus Planting Calendar

Activity When Date Range
Transplant Outdoors June 3 Jun 3 โ€“ Jun 17

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 โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

730โ€“1095 days

Soil pH

6.5 โ€“ 7.5

USDA Zone

Zone 4a

Growing Season

131 days

Growing Tips for Oneida County

Plant crowns in deep trenches with compost. Do not harvest spears for the first two years to allow root establishment. Mulch heavily to suppress weeds and retain moisture.

Companion Planting

Good Companions

Avoid Planting Near

  • Garlic
  • Onion

Level Up Your Garden

Frequently Asked Questions

When should I plant Asparagus in Oneida County, WI?

Oneida County is in Zone 4a with an average last frost of May 20. Plan your Asparagus planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Oneida County, WI?

Oneida County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is May 20 and first fall frost is September 28.

๐ŸŒฑ

Plan Your Garden with Confidence

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