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When to Plant Scarlet Runner Beans in Chatham County, NC

Chatham County, North Carolina Zone 8a May

Chatham County, North Carolina gardeners: here's your May plan

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

Avg. last frost March 28
Avg. first frost November 6
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Start scarlet runner beans under lights

    Your window is short. These crops want several weeks of indoor growth before they go outside.

Coming up in June — start thinking about
  • First harvests: scarlet runner beans

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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.

Chatham County, North Carolina is in USDA Zone 8a. The average last spring frost is March 28 and the first fall frost is November 6, giving you a growing season of approximately 223 days.

At an elevation of 1,042 feet, Chatham County receives approximately 48.2 inches of rainfall annually with predominantly clay loam soil. Summer highs average 90°F, providing good warmth for Scarlet Runner Beans during the growing season. Clay soil retains moisture well for Scarlet Runner Beans, but amend with compost to improve drainage and prevent root rot.

Chatham County, NC (Zone 8a) Long season
223 days
Last Spring Frost March 28
223 growing days
First Fall Frost November 6

Chatham County Soil Profile

Soil Type

Clay Loam

Soil pH

5.5-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (113 days to spare)
Start indoors: Feb 1 Transplant: Apr 5 🍅 Harvest: Jun 7 – Jul 12
Recommended (50%) ✓ Fits season (111 days to spare)
Start indoors: Feb 7 Transplant: Apr 11 🍅 Harvest: Jun 13 – Jul 18
Safe Start (90%) ✓ Fits season (105 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Jul 1 – Aug 5

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 Chatham County

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

Soil pH

Your soil pH (5.5–6.4) is more acidic than Scarlet Runner Beans prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The clay loam soil in Chatham County is excellent for Scarlet Runner Beans — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Scarlet Runner Beans.

How to Plant Scarlet Runner Beans

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

Succession Planting Scarlet Runner Beans

4
successive plantings in your 223-day season

Sow every 6.9 weeks. Last sowing by Aug 18 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 183 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 4.2" 0" ❄️ Dormant
Feb 3.7" 0" ❄️ Dormant
Mar 4.3" 4.3" 0" ✅ Rainfall sufficient
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 4.5" 0" ✅ Rainfall sufficient
Sep 4.3" 4.2" 0.1" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 4.3" 4.2" 0.1" 💧 Light watering
Dec 3.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Chatham County). Supplement amounts are based on average rainfall — 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" — 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.

Scarlet Runner Beans needs ~1,225 GDD — county provides 3,902 GDD Excellent fit

Scarlet Runner Beans Planting Timeline — Chatham County, NC

Scarlet Runner Beans Planting Calendar

Activity When Date Range
Start Indoors February 7 Feb 7 – Feb 21
Transplant Outdoors April 11 Apr 11 – Apr 25
Direct Sow April 4 Apr 4 – Apr 25
Harvest June 13 Jun 13 – Jul 18

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8a

📆 Growing Season

223 days in Chatham County

Growing Tips for Scarlet Runner Beans in Chatham County

Direct sow Scarlet Runner Beans outdoors after March 28 in Chatham County when soil has warmed and frost danger has passed.

With Chatham County's clay soil (28% clay), work in 3-4 inches of compost before planting Scarlet Runner Beans. Avoid tilling when soil is wet to prevent compaction.

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 Chatham County, NC?

Chatham County is in Zone 8a with an average last frost of March 28. Plan your Scarlet Runner Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Chatham County, NC?

Chatham County, North Carolina is in USDA Hardiness Zone 8a. The average last spring frost is March 28 and first fall frost is November 6.

🌱

Your Chatham County Garden Planner — Free

A 24-page printable planner built for Chatham County (Zone 8a). 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 Chatham County, NC. 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.