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When to Plant Onion in Clearfield County, PA

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.

Clearfield County, Pennsylvania is in USDA Zone 5b. The average last spring frost is May 2 and the first fall frost is October 18, giving you a growing season of approximately 169 days.

At an elevation of 69 feet, Clearfield County receives approximately 47 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Onion to ensure they mature before fall.

Clearfield County, PA (Zone 5b) Moderate season
169 days
Last Spring Frost May 2
169 growing days
First Fall Frost October 18

Clearfield County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jul 27 – Sep 14
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Aug 1 – Sep 19
Safe Start (90%) ✓ Fits season (23 days to spare)
Start indoors: Apr 18 Transplant: May 23 🍅 Harvest: Aug 22 – Oct 10

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Onion needs ~1,286 GDD — county provides 2,070 GDD Excellent fit

Onion Planting Timeline โ€” Clearfield County, PA

Onion Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 โ€“ Apr 11
Transplant Outdoors May 2 May 2 โ€“ May 16
Direct Sow April 18 Apr 18 โ€“ May 9
Fall Sowing August 9 Aug 9 โ€“ Aug 23
Harvest August 1 Aug 1 โ€“ Sep 19

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

90โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

169 days

Growing Tips for Clearfield County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Onion in Clearfield County, PA?

Clearfield County is in Zone 5b with an average last frost of May 2. Plan your Onion planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clearfield County, PA?

Clearfield County, Pennsylvania is in USDA Hardiness Zone 5b. The average last spring frost is May 2 and first fall frost is October 18.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Clearfield County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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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 Clearfield County, PA. Local conditions may vary. Last updated: April 2026.