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When to Plant Scarlet Runner Beans in Benton County, TN

Benton County, Tennessee Zone 7b May

Your May game plan for Benton County, Tennessee

A quick May briefing for Benton County, Tennessee gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 7
Avg. first frost October 28
Soil temp (4") 58°F
Watering Moderate
Pest pressure Moderate
Daylight 13.9 hrs
  1. Time to start scarlet runner beans inside

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

A few tasks this May that'll pay off in June
  • 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.

Benton County, Tennessee is in USDA Zone 7b. The average last spring frost is April 7 and the first fall frost is October 28, giving you a growing season of approximately 204 days.

At an elevation of 3,295 feet, Benton County receives approximately 46.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Scarlet Runner Beans during the growing season.

Benton County, TN (Zone 7b) Long season
204 days
Last Spring Frost April 7
204 growing days
First Fall Frost October 28
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Benton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (92 days to spare)
Start indoors: Feb 10 Transplant: Apr 14 🍅 Harvest: Jun 16 – Jul 21
Recommended (50%) ✓ Fits season (92 days to spare)
Start indoors: Feb 17 Transplant: Apr 21 🍅 Harvest: Jun 23 – Jul 28
Safe Start (90%) ✓ Fits season (93 days to spare)
Start indoors: Mar 4 Transplant: May 6 🍅 Harvest: Jul 8 – Aug 12

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 Benton County

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

Soil pH

Your soil pH (5.5–7.1) overlaps with Scarlet Runner Beans's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). 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 204-day season

Sow every 6.9 weeks. Last sowing by Aug 09 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 62 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 3.8" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 4.3" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 5.2" 0" ✅ Rainfall sufficient
Aug 4.3" 5.1" 0" ✅ Rainfall sufficient
Sep 4.3" 3.8" 0.5" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 4.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Benton 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 ~1,278 GDD — county provides 3,723 GDD Excellent fit

Scarlet Runner Beans Planting Timeline — Benton County, TN

Scarlet Runner Beans Planting Calendar

Activity When Date Range
Start Indoors February 17 Feb 17 – Mar 3
Transplant Outdoors April 21 Apr 21 – May 5
Direct Sow April 14 Apr 14 – May 5
Harvest June 23 Jun 23 – Jul 28

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 7b

📆 Growing Season

204 days in Benton County

Growing Tips for Scarlet Runner Beans in Benton County

Direct sow Scarlet Runner Beans outdoors after April 07 in Benton 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 Benton County, TN?

Benton County is in Zone 7b with an average last frost of April 7. Plan your Scarlet Runner Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Benton County, TN?

Benton County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 7 and first fall frost is October 28.

🌱

Your Benton County Garden Planner — Free

A 24-page printable planner built for Benton County (Zone 7b). 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 Benton County, TN. 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.