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When to Plant Scarlet Runner Beans in Yamhill County, OR

Scarlet runner beans are ornamental and edible climbing beans with vivid red flowers that attract hummingbirds. Both the young pods and mature beans are edible.

Yamhill County, Oregon is in USDA Zone 8a. The average last spring frost is April 15 and the first fall frost is October 27, giving you a growing season of approximately 195 days.

At an elevation of 476 feet, Yamhill County receives approximately 54.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Scarlet Runner Beans during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Scarlet Runner Beans root diseases.

Yamhill County, OR (Zone 8a) Moderate season
195 days
Last Spring Frost April 15
195 growing days
First Fall Frost October 27

Yamhill County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (81 days to spare)
Start indoors: Feb 18 Transplant: Apr 22 🍅 Harvest: Jun 24 – Jul 29
Recommended (50%) ✓ Fits season (83 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Jul 1 – Aug 5
Safe Start (90%) ✓ Fits season (84 days to spare)
Start indoors: Mar 20 Transplant: May 22 🍅 Harvest: Jul 24 – Aug 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.

Soil Compatibility in Yamhill County

How your county's soil matches Scarlet Runner Beans's growing requirements.

Soil pH

Your soil pH (5.4โ€“6.2) is more acidic than Scarlet Runner Beans prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Yamhill County is excellent for Scarlet Runner Beans โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Scarlet Runner Beans.

Organic Matter

Organic matter is excellent (4.3%) โ€” Scarlet Runner Beans will thrive.

How to Plant Scarlet Runner Beans

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

Succession Planting Scarlet Runner Beans

3
successive plantings in your 195-day season

Sow every 6.9 weeks. Last sowing by Aug 08 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 215 gal / 100 sq ft

Monthly Watering Guide for Scarlet Runner Beans

Scarlet Runner 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 Scarlet Runner Beans Needs Rainfall You Supplement Action
Jan โ€” 7.4" 0" โ„๏ธ Dormant
Feb โ€” 6.4" 0" โ„๏ธ Dormant
Mar โ€” 5.1" 0" โ„๏ธ Dormant
Apr 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
May 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
Jun 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Jul 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Aug 4.3" 1" 3.3" ๐Ÿšฟ Regular watering
Sep 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Oct 4.3" 4.8" 0" โœ… Rainfall sufficient
Nov โ€” 9.3" 0" โ„๏ธ Dormant
Dec โ€” 8.8" 0" โ„๏ธ Dormant

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

Scarlet Runner 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" 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.

Scarlet Runner Beans needs ~1,225 GDD — county provides 3,412 GDD Excellent fit

Scarlet Runner Beans Planting Timeline โ€” Yamhill County, OR

Scarlet Runner Beans Planting Calendar

Activity When Date Range
Start Indoors February 25 Feb 25 โ€“ Mar 11
Transplant Outdoors April 29 Apr 29 โ€“ May 13
Direct Sow April 22 Apr 22 โ€“ May 13
Harvest July 1 Jul 1 โ€“ Aug 5

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

60โ€“80 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

195 days in Yamhill County

Growing Tips for Scarlet Runner Beans in Yamhill County

Direct sow Scarlet Runner Beans outdoors after April 15 in Yamhill County when soil has warmed and frost danger has passed.

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

General growing tips

Provide tall trellising for vigorous vines. Direct sow after frost. Harvest pods young for snap beans or let mature for shelling beans. Tubers are perennial in mild climates.

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 Scarlet Runner Beans in Yamhill County, OR?

Yamhill County is in Zone 8a with an average last frost of April 15. Plan your Scarlet Runner Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Yamhill County, OR?

Yamhill County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is April 15 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Yamhill County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Yamhill County, OR. Local conditions may vary. Last updated: April 2026.