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When to Plant Yard Long Beans in Union County, OR

Yard long beans are a tropical legume that produces slender pods up to 24 inches long. They are a staple in Southeast Asian cooking and thrive in hot weather.

Union County, Oregon is in USDA Zone 5b. The average last spring frost is May 12 and the first fall frost is September 26, giving you a growing season of approximately 137 days.

At an elevation of 2,751 feet, Union County receives approximately 23.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Yard Long Beans during the growing season.

Union County, OR (Zone 5b) Short season
137 days
Last Spring Frost May 12
137 growing days
First Fall Frost September 26

Union County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (22 days to spare)
Start indoors: Mar 8 Transplant: May 17 🍅 Harvest: Jul 12 – Aug 23
Recommended (50%) ✓ Fits season (25 days to spare)
Start indoors: Mar 17 Transplant: May 26 🍅 Harvest: Jul 21 – Sep 1
Safe Start (90%) ✓ Fits season (21 days to spare)
Start indoors: Apr 13 Transplant: Jun 22 🍅 Harvest: Aug 17 – Sep 28

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
0.7″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 707 gal / 100 sq ft
Yard Long Beans needs ~979 GDD — county provides 1,986 GDD Excellent fit

Yard Long Beans Planting Timeline โ€” Union County, OR

Yard Long Beans Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 โ€“ Mar 31
Transplant Outdoors May 26 May 26 โ€“ Jun 9
Direct Sow May 19 May 19 โ€“ Jun 9
Harvest July 21 Jul 21 โ€“ Sep 1

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April โ€”
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Harvest
August 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

55โ€“80 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 5b

Growing Season

137 days

Growing Tips for Union County

Direct sow after soil is warm. Provide tall poles or trellising as vines can reach 8-10 feet. Harvest when pods are pencil-thick before seeds bulge. Cook quickly for best texture.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Level Up Your Garden

Frequently Asked Questions

When should I plant Yard Long Beans in Union County, OR?

Union County is in Zone 5b with an average last frost of May 12. Plan your Yard Long Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Union County, OR?

Union County, Oregon is in USDA Hardiness Zone 5b. The average last spring frost is May 12 and first fall frost is September 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Union 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 Union County, OR. Local conditions may vary. Last updated: April 2026.