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When to Plant Celery in Waterloo, OH

Celery
Waterloo, OH Zone 7a June

Top priorities for Waterloo, OH gardeners in June

Welcome to June in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 23
Avg. first frost October 21
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
Looking ahead to July
  • First harvests: celery

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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.

Waterloo, Ohio is in USDA Zone 7a. The average last spring frost is April 23 and the first fall frost is October 21, giving you a growing season of approximately 181 days.

At an elevation of 1,332 feet, Lawrence County receives approximately 37.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Celery during the growing season.

Waterloo, OH (Zone 7a) Moderate season
181 days
Last Spring Frost April 23
181 growing days
First Fall Frost October 21
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Waterloo Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.3

Drainage

Well Drained

Celery Planting Risk Windows

Early Start (70% safe) ✓ Fits season (46 days to spare)
Start indoors: Mar 10 Transplant: Apr 14 🍅 Harvest: Jul 7 – Sep 1
Recommended (50%) ✓ Fits season (41 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Jul 16 – Sep 10
Safe Start (90%) ✓ Fits season (36 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Aug 2 – Sep 27

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 Waterloo

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

Soil pH

Your soil pH (5.8–7.3) overlaps with Celery's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Lawrence County is excellent for Celery — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.8%) — Celery will thrive.

How to Plant Celery

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Celery

2
successive plantings in your 181-day season

Sow every 9.1 weeks. Last sowing by Jun 23 to harvest before frost.

For a dedicated fall crop, sow by Aug 12.

Celery Water Budget

Plant needs
1.3″/week
Rainfall provides
0.9″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 817 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.4" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 5.6" 4" 1.6" 💧 Light watering
May 5.6" 4.4" 1.2" 💧 Light watering
Jun 5.6" 5.1" 0.5" 💧 Light watering
Jul 5.6" 3.7" 1.9" 💧 Light watering
Aug 5.6" 4.3" 1.3" 💧 Light watering
Sep 5.6" 3.4" 2.2" 💧 Light watering
Oct 5.6" 3.1" 2.5" 💧 Light watering
Nov 2.2" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Lawrence County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~1,675 GDD — county provides 3,031 GDD Excellent fit

Celery Planting Timeline — Waterloo, OH

Celery Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 9 Apr 9 – Apr 30
Harvest July 16 Jul 16 – Sep 10
Fall Sowing August 12 Aug 12 – Aug 26

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.3"/week · 1-2 times/week

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

181 days in Lawrence County

Growing Tips for Celery in Waterloo

Direct sow Celery outdoors after April 23 in Lawrence 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 →

🌱

Your Lawrence County Garden Planner — Free

A 22-page printable planner built for Lawrence County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Lawrence County, OH. Local conditions may vary. Last updated: June 2026.