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When to Plant Celery in Marathon County, WI

Celery is a marshland plant that requires consistent moisture and cool temperatures to produce crisp, flavorful stalks. It is a rewarding but demanding garden crop.

Marathon County, Wisconsin is in USDA Zone 4a. The average last spring frost is May 11 and the first fall frost is October 2, giving you a growing season of approximately 144 days.

At an elevation of 723 feet, Marathon County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Celery to ensure they mature before fall.

Marathon County, WI (Zone 4a) Short season
144 days
Last Spring Frost May 11
144 growing days
First Fall Frost October 2

Marathon County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Monthly Watering Guide for Celery

Celery needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Celery Needs Rainfall You Supplement Action
Jan โ€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 2" 0" โ„๏ธ Dormant
Mar โ€” 2.7" 0" โ„๏ธ Dormant
Apr โ€” 4.3" 0" โ„๏ธ Dormant
May 4.3" 5" 0" โœ… Rainfall sufficient
Jun 4.3" 4.5" 0" โœ… Rainfall sufficient
Jul 4.3" 4.8" 0" โœ… Rainfall sufficient
Aug 4.3" 4.6" 0" โœ… Rainfall sufficient
Sep 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Oct 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Nov โ€” 2.4" 0" โ„๏ธ Dormant
Dec โ€” 1.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Marathon County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Celery Planting Timeline โ€” Marathon County, WI

Celery Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 โ€“ Apr 13
Transplant Outdoors May 11 May 11 โ€“ May 25
Direct Sow May 4 May 4 โ€“ May 25
Harvest August 3 Aug 3 โ€“ Sep 28
Fall Sowing July 10 Jul 10 โ€“ Jul 24

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

High โ€” keep soil consistently moist

๐Ÿ“… Days to Maturity

80โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

144 days in Marathon County

Growing Tips for Marathon County

Start seeds indoors 10-12 weeks before last frost. Keep soil consistently moist and never let it dry out. Blanch stalks by mounding soil or using collars for milder flavor.

Companion Planting

Good Companions

Avoid Planting Near

  • Carrots
  • Parsnip

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Celery in Marathon County, WI?

Marathon County is in Zone 4a with an average last frost of May 11. Plan your Celery planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Marathon County, WI?

Marathon County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is May 11 and first fall frost is October 2.

๐ŸŒฑ

Plan Your Garden with Confidence

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