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When to Plant Celery in Oxford County, ME

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.

Oxford County, Maine is in USDA Zone 4b. The average last spring frost is May 16 and the first fall frost is September 29, giving you a growing season of approximately 136 days.

At an elevation of 186 feet, Oxford County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Celery to ensure they mature before fall.

Oxford County, ME (Zone 4b) Short season
136 days
Last Spring Frost May 16
136 growing days
First Fall Frost September 29

Oxford County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 30 Transplant: May 11 🍅 Harvest: Aug 3 – Sep 28
Recommended (50%) ✗ May not fit
Start indoors: Apr 4 Transplant: May 16 🍅 Harvest: Aug 8 – Oct 3
Safe Start (90%) ✗ May not fit
Start indoors: Apr 18 Transplant: May 30 🍅 Harvest: Aug 22 – Oct 17

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.

Soil Compatibility in Oxford County

How your county's soil matches Celery's growing requirements.

Soil pH

Your soil pH (4.9โ€“6.4) is more acidic than Celery prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Oxford County is excellent for Celery โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Celery.

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Celery.

How to Plant Celery

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Celery

Celery needs approximately 1.3 inches of water per week (5.6" per month). Here's how your county's rainfall compares month by month.

Month Celery Needs Rainfall You Supplement Action
Jan โ€” 2.7" 0" โ„๏ธ Dormant
Feb โ€” 2.8" 0" โ„๏ธ Dormant
Mar โ€” 3.5" 0" โ„๏ธ Dormant
Apr โ€” 3.7" 0" โ„๏ธ Dormant
May 5.6" 3.8" 1.8" ๐Ÿ’ง Light watering
Jun 5.6" 3.6" 2" ๐Ÿ’ง Light watering
Jul 5.6" 3.7" 1.9" ๐Ÿ’ง Light watering
Aug 5.6" 3.6" 2" ๐Ÿ’ง Light watering
Sep 5.6" 3.3" 2.3" ๐Ÿ’ง Light watering
Oct โ€” 2.8" 0" โ„๏ธ Dormant
Nov โ€” 3.4" 0" โ„๏ธ Dormant
Dec โ€” 3" 0" โ„๏ธ Dormant

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

Celery Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Celery needs ~1,150 GDD — county provides 1,564 GDD Excellent fit

Celery Planting Timeline โ€” Oxford County, ME

Celery Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 โ€“ Apr 18
Transplant Outdoors May 16 May 16 โ€“ May 30
Direct Sow May 9 May 9 โ€“ May 30
Harvest August 8 Aug 8 โ€“ Oct 3
Fall Sowing July 7 Jul 7 โ€“ Jul 21

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.3"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

80โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

136 days in Oxford County

Growing Tips for Celery in Oxford County

Direct sow Celery outdoors after May 16 in Oxford County when soil has warmed and frost danger has passed.

Common pests for Celery in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

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 Oxford County, ME?

Oxford County is in Zone 4b with an average last frost of May 16. Plan your Celery planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Oxford County, ME?

Oxford County, Maine is in USDA Hardiness Zone 4b. The average last spring frost is May 16 and first fall frost is September 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Oxford 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 Oxford County, ME. Local conditions may vary. Last updated: April 2026.