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When to Plant Onion in Cattaraugus County, NY

Cattaraugus County, New York Zone 5b May

May in Cattaraugus County, New York — your action list

Each item below is timed to Cattaraugus County, New York's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 22
Avg. first frost October 2
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 14.4 hrs
  1. Plant out onion

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Direct-sow onion

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

Get ahead of June
  • Starting indoors: onion

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Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.

Cattaraugus County, New York is in USDA Zone 5b. The average last spring frost is May 22 and the first fall frost is October 2, giving you a growing season of approximately 133 days.

At an elevation of 486 feet, Cattaraugus County receives approximately 43.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Onion during the growing season.

Cattaraugus County, NY (Zone 5b) Short season
133 days
Last Spring Frost May 22
133 growing days
First Fall Frost October 2
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Cattaraugus County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 12 Transplant: May 17 🍅 Harvest: Aug 16 – Oct 4
Recommended (50%) ✗ May not fit
Start indoors: Apr 17 Transplant: May 22 🍅 Harvest: Aug 21 – Oct 9
Safe Start (90%) ✗ May not fit
Start indoors: May 4 Transplant: Jun 8 🍅 Harvest: Sep 7 – Oct 26

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 Cattaraugus County

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

Soil pH

Your soil pH (5.2–6.6) is more acidic than Onion prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Onion.

How to Plant Onion

1"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Plant Water Budget

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

Monthly Watering Guide for Onion

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

Month Onion Needs Rainfall You Supplement Action
Jan 3.4" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 3.6" 0" ❄️ Dormant
Apr 3.8" 0" ❄️ Dormant
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 4.7" 0" ✅ Rainfall sufficient
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 3.7" 0" ❄️ Dormant
Dec 2.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Cattaraugus County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Onion 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.

Onion needs ~1,522 GDD — county provides 1,928 GDD Good fit

Onion Planting Timeline — Cattaraugus County, NY

Onion Planting Calendar

Activity When Date Range
Start Indoors April 17 Apr 17 – May 1
Transplant Outdoors May 22 May 22 – Jun 5
Direct Sow May 8 May 8 – May 29
Harvest August 21 Aug 21 – Oct 9
Fall Sowing July 24 Jul 24 – Aug 7

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

133 days in Cattaraugus County

Growing Tips for Onion in Cattaraugus County

Direct sow Onion outdoors after May 22 in Cattaraugus County when soil has warmed and frost danger has passed.

Your 133.0-day growing season in Cattaraugus County is tight for Onion (90.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Onion in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Onion in Cattaraugus County, NY?

Cattaraugus County is in Zone 5b with an average last frost of May 22. Plan your Onion planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cattaraugus County, NY?

Cattaraugus County, New York is in USDA Hardiness Zone 5b. The average last spring frost is May 22 and first fall frost is October 2.

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Your Cattaraugus County Garden Planner — Free

A 24-page printable planner built for Cattaraugus 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 Cattaraugus 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.