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When to Plant Yard Long Beans in Clackamas County, OR

Clackamas County, Oregon Zone 9a May

What to do in May

Your garden in Clackamas County, Oregon is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 14
Avg. first frost October 28
Soil temp (4") 73°F
Watering Moderate
Pest pressure High
Daylight 14.7 hrs
  1. Start yard long beans indoors

    These need a head start before your last frost (April 14). Sow into cells now so you're ready to transplant in a few weeks.

Get ahead of June
  • First harvests: yard long beans

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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.

Clackamas County, Oregon is in USDA Zone 9a. The average last spring frost is April 14 and the first fall frost is October 28, giving you a growing season of approximately 197 days.

At an elevation of 199 feet, Clackamas County receives approximately 53.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Yard Long Beans during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Yard Long Beans root diseases.

Clackamas County, OR (Zone 9a) Moderate season
197 days
Last Spring Frost April 14
197 growing days
First Fall Frost October 28

Clackamas County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (92 days to spare)
Start indoors: Feb 21 Transplant: Apr 11 🍅 Harvest: Jun 6 – Jul 18
Recommended (50%) ✓ Fits season (92 days to spare)
Start indoors: Mar 3 Transplant: Apr 21 🍅 Harvest: Jun 16 – Jul 28
Safe Start (90%) ✓ Fits season (96 days to spare)
Start indoors: Mar 26 Transplant: May 14 🍅 Harvest: Jul 9 – Aug 20

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 Clackamas County

How your county's soil matches Yard Long Beans's growing requirements.

Soil pH

Your soil pH (5.7–6.3) overlaps with Yard Long Beans's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Clackamas County is excellent for Yard Long Beans — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.7%) — Yard Long Beans will thrive.

How to Plant Yard Long Beans

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

Succession Planting Yard Long Beans

4
successive plantings in your 197-day season

Sow every 6.3 weeks. Last sowing by Aug 09 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Yard Long Beans

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

Month Yard Long Beans Needs Rainfall You Supplement Action
Jan 8.3" 0" ❄️ Dormant
Feb 5.3" 0" ❄️ Dormant
Mar 4.8" 0" ❄️ Dormant
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 2.1" 2.2" 🚿 Regular watering
Jul 4.3" 0.8" 3.5" 🚿 Regular watering
Aug 4.3" 1" 3.3" 🚿 Regular watering
Sep 4.3" 2.2" 2.1" 💧 Light watering
Oct 4.3" 4.7" 0" ✅ Rainfall sufficient
Nov 8.2" 0" ❄️ Dormant
Dec 8.5" 0" ❄️ Dormant

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

Yard Long Beans 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.

Yard Long Beans needs ~928 GDD — county provides 2,708 GDD Excellent fit

Yard Long Beans Planting Timeline — Clackamas County, OR

Yard Long Beans Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 – Mar 17
Transplant Outdoors April 21 Apr 21 – May 5
Direct Sow April 14 Apr 14 – May 5
Harvest June 16 Jun 16 – Jul 28

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

55–80 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

197 days in Clackamas County

Growing Tips for Yard Long Beans in Clackamas County

Direct sow Yard Long Beans outdoors after April 14 in Clackamas County when soil has warmed and frost danger has passed.

Common pests for Yard Long Beans 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 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

Clackamas County is in Zone 9a with an average last frost of April 14. Plan your Yard Long Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clackamas County, OR?

Clackamas County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is April 14 and first fall frost is October 28.

🌱

Your Clackamas County Garden Planner — Free

A 24-page printable planner built for Clackamas County (Zone 9a). 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 Clackamas County, OR. 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.