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When to Plant Napa Cabbage in Ontario County, NY

Ontario County, New York Zone 5b April

April in Ontario County, New York — your action list

April rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Ontario County, New York.

Avg. last frost April 29
Avg. first frost October 20
Soil temp (4") 44°F
Watering Low
Pest pressure Low
Daylight 13.2 hrs
  1. Transplant napa cabbage outside

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Put napa cabbage seeds straight in the ground

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

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Napa cabbage forms tall, barrel-shaped heads with tender, crinkled leaves and a mild, slightly sweet flavor. It is the primary cabbage used for kimchi.

Ontario County, New York is in USDA Zone 5b. 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 Napa Cabbage to ensure they mature before fall.

Ontario County, NY (Zone 5b) Moderate season
174 days
Last Spring Frost April 29
174 growing days
First Fall Frost October 20
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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 (79 days to spare)
Start indoors: Mar 22 Transplant: Apr 26 🍅 Harvest: Jun 21 – Jul 26
Recommended (50%) ✓ Fits season (83 days to spare)
Start indoors: Mar 25 Transplant: Apr 29 🍅 Harvest: Jun 24 – Jul 29
Safe Start (90%) ✓ Fits season (82 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: Jul 9 – Aug 13

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 Napa Cabbage's growing requirements.

Soil pH

Your soil pH (4.9–6.6) is more acidic than Napa Cabbage prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

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

How to Plant Napa Cabbage

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 Napa Cabbage

3
successive plantings in your 174-day season

Sow every 6.3 weeks. Last sowing by Aug 06 to harvest before frost.

For a dedicated fall crop, sow by Aug 11.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.2″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 454 gal / 100 sq ft

Monthly Watering Guide for Napa Cabbage

Napa Cabbage needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Napa Cabbage Needs Rainfall You Supplement Action
Jan 3.3" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 6.5" 3.8" 2.7" 💧 Light watering
May 6.5" 4.8" 1.7" 💧 Light watering
Jun 6.5" 5" 1.5" 💧 Light watering
Jul 6.5" 4.7" 1.8" 💧 Light watering
Aug 6.5" 4.4" 2.1" 💧 Light watering
Sep 6.5" 4.4" 2.1" 💧 Light watering
Oct 6.5" 4.1" 2.4" 💧 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.

Napa Cabbage 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.

Napa Cabbage needs ~845 GDD — county provides 2,262 GDD Excellent fit

Napa Cabbage Planting Timeline — Ontario County, NY

Napa Cabbage 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 June 24 Jun 24 – Jul 29
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 Harvest
July Harvest
August Fall Sowing
September
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

174 days in Ontario County

Growing Tips for Napa Cabbage in Ontario County

Direct sow Napa Cabbage outdoors after April 29 in Ontario County when soil has warmed and frost danger has passed.

Common pests for Napa Cabbage in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Best grown as a fall crop. Direct sow in late summer, 60-70 days before first frost. Keep soil evenly moist. Bolt-resistant varieties are available for spring planting.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Napa Cabbage in Ontario County, NY?

Ontario County is in Zone 5b with an average last frost of April 29. Plan your Napa Cabbage 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 5b. 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 5b). 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 Ontario County, NY. Local conditions may vary. Last updated: April 2026.

Sources & credits

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