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When to Plant Celery in Ontario County, NY

Ontario County, New York Zone 6b May

May in the garden — Ontario County, New York

Your Ontario County, New York garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost April 29
Avg. first frost October 20
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
To set up a strong June, finish these tasks
  • Starting indoors: 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.

Ontario County, New York is in USDA Zone 6b. The average last spring frost is April 29 and the first fall frost is October 20, giving you a growing season of approximately 174 days.

At an elevation of 33 feet, Ontario County receives approximately 50 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Celery to ensure they mature before fall.

Ontario County, NY (Zone 6b) Moderate season
174 days
Last Spring Frost April 29
174 growing days
First Fall Frost October 20

Ontario County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (30 days to spare)
Start indoors: Mar 22 Transplant: Apr 26 🍅 Harvest: Jul 19 – Sep 13
Recommended (50%) ✓ Fits season (34 days to spare)
Start indoors: Mar 25 Transplant: Apr 29 🍅 Harvest: Jul 22 – Sep 16
Safe Start (90%) ✓ Fits season (33 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: Aug 6 – Oct 1

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 Ontario County

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

Soil pH

Your soil pH (4.9–6.6) is more acidic than Celery prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Celery.

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 174-day season

Sow every 9.1 weeks. Last sowing by Jun 22 to harvest before frost.

For a dedicated fall crop, sow by Aug 11.

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
1.2″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 144 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 3.3" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 5.6" 3.8" 1.8" 💧 Light watering
May 5.6" 4.8" 0.8" 💧 Light watering
Jun 5.6" 5" 0.6" 💧 Light watering
Jul 5.6" 4.7" 0.9" 💧 Light watering
Aug 5.6" 4.4" 1.2" 💧 Light watering
Sep 5.6" 4.4" 1.2" 💧 Light watering
Oct 5.6" 4.1" 1.5" 💧 Light watering
Nov 4.1" 0" ❄️ Dormant
Dec 4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Ontario 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 ~1,300 GDD — county provides 2,262 GDD Excellent fit

Celery Planting Timeline — Ontario County, NY

Celery Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 – Apr 8
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 15 Apr 15 – May 6
Harvest July 22 Jul 22 – Sep 16
Fall Sowing August 11 Aug 11 – Aug 25

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 Direct Sow
June
July Harvest
August Fall Sowing Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.3"/week · Only during dry spells

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

174 days in Ontario County

Growing Tips for Celery in Ontario County

Direct sow Celery outdoors after April 29 in Ontario 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 Ontario County, NY?

Ontario County is in Zone 6b with an average last frost of April 29. Plan your Celery planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ontario County, NY?

Ontario County, New York is in USDA Hardiness Zone 6b. The average last spring frost is April 29 and first fall frost is October 20.

🌱

Your Ontario County Garden Planner — Free

A 24-page printable planner built for Ontario County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Ontario County, NY. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.