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When to Plant Soybeans in Clarion County, PA

Soybeans (edamame) are a high-protein legume that fixes nitrogen in the soil. Fresh green soybeans harvested at the edamame stage are a nutritious snack.

Clarion County, Pennsylvania is in USDA Zone 5b. The average last spring frost is May 9 and the first fall frost is October 15, giving you a growing season of approximately 159 days.

At an elevation of 840 feet, Clarion County receives approximately 44.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Soybeans to ensure they mature before fall.

Clarion County, PA (Zone 5b) Moderate season
159 days
Last Spring Frost May 9
159 growing days
First Fall Frost October 15

Clarion County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (20 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 23 – Sep 17
Recommended (50%) ✓ Fits season (19 days to spare)
Transplant: May 9 🍅 Harvest: Aug 1 – Sep 26
Safe Start (90%) ✓ Fits season (18 days to spare)
Transplant: May 26 🍅 Harvest: Aug 18 – Oct 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 Clarion County

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

Soil pH

Your soil pH (4.8โ€“6.8) is more acidic than Soybeans prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Clarion County is excellent for Soybeans โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Soybeans.

How to Plant Soybeans

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

Succession Planting Soybeans

2
successive plantings in your 159-day season

Sow every 9.1 weeks. Last sowing by Jun 17 to harvest before frost.

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

Monthly Watering Guide for Soybeans

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

Month Soybeans Needs Rainfall You Supplement Action
Jan โ€” 3" 0" โ„๏ธ Dormant
Feb โ€” 3.5" 0" โ„๏ธ Dormant
Mar โ€” 4" 0" โ„๏ธ Dormant
Apr โ€” 3.8" 0" โ„๏ธ Dormant
May 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Jun 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Jul 4.3" 4.7" 0" โœ… Rainfall sufficient
Aug 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Sep 4.3" 4.4" 0" โœ… Rainfall sufficient
Oct 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Nov โ€” 3.2" 0" โ„๏ธ Dormant
Dec โ€” 3.3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Clarion County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Soybeans 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" โ€” every day above 50ยฐF 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.

Soybeans needs ~1,300 GDD — county provides 2,067 GDD Excellent fit

Soybeans Planting Timeline โ€” Clarion County, PA

Soybeans Planting Calendar

Activity When Date Range
Direct Sow May 16 May 16 โ€“ Jun 6
Harvest August 8 Aug 8 โ€“ Oct 3

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Direct Sow
June Direct Sow
July โ€”
August Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

80โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

159 days in Clarion County

Growing Tips for Soybeans in Clarion County

Direct sow Soybeans outdoors after May 09 in Clarion County when soil has warmed and frost danger has passed.

Common pests for Soybeans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after soil warms to 60F. Plant in blocks rather than rows for better pollination. Harvest for edamame when pods are plump and bright green.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Soybeans in Clarion County, PA?

Clarion County is in Zone 5b with an average last frost of May 9. Plan your Soybeans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clarion County, PA?

Clarion County, Pennsylvania is in USDA Hardiness Zone 5b. The average last spring frost is May 9 and first fall frost is October 15.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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