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When to Plant Scarlet Runner Beans in Tarrant County, TX

Tarrant County, Texas Zone 8b May

Your May game plan for Tarrant County, Texas

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

Avg. last frost March 18
Avg. first frost November 12
Soil temp (4") 65°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
  1. Fire up the seed-starting tray: scarlet runner beans

    These need a head start before your last frost (March 18). Sow into cells now so you're ready to transplant in a few weeks.

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.

Tarrant County, Texas is in USDA Zone 8b. The average last spring frost is March 18 and the first fall frost is November 12, giving you a growing season of approximately 239 days.

At an elevation of 3,487 feet, Tarrant County receives approximately 63.1 inches of rainfall annually with predominantly clay soil. Summer highs average 92°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. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Scarlet Runner Beans root diseases.

Tarrant County, TX (Zone 8b) Long season
239 days
Last Spring Frost March 18
239 growing days
First Fall Frost November 12

Tarrant County Soil Profile

Soil Type

Clay

Soil pH

7.3-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (135 days to spare)
Start indoors: Jan 16 Transplant: Mar 20 🍅 Harvest: May 22 – Jun 26
Recommended (50%) ✓ Fits season (127 days to spare)
Start indoors: Jan 28 Transplant: Apr 1 🍅 Harvest: Jun 3 – Jul 8
Safe Start (90%) ✓ Fits season (124 days to spare)
Start indoors: Feb 22 Transplant: Apr 26 🍅 Harvest: Jun 28 – Aug 2

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 Tarrant County

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

Soil pH

Your soil pH (7.3–8.1) is more alkaline than Scarlet Runner Beans prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (45% clay) in Tarrant County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (3.1%). 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 239-day season

Sow every 6.9 weeks. Last sowing by Aug 24 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 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 1.8" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 4.3" 3.8" 0.5" 💧 Light watering
Apr 4.3" 7" 0" ✅ Rainfall sufficient
May 4.3" 9.8" 0" ✅ Rainfall sufficient
Jun 4.3" 10.1" 0" ✅ Rainfall sufficient
Jul 4.3" 7.2" 0" ✅ Rainfall sufficient
Aug 4.3" 8.1" 0" ✅ Rainfall sufficient
Sep 4.3" 5.5" 0" ✅ Rainfall sufficient
Oct 4.3" 4.1" 0.2" 💧 Light watering
Nov 4.3" 2.2" 2.1" 💧 Light watering
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Tarrant 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 ~1,330 GDD — county provides 4,541 GDD Excellent fit

Scarlet Runner Beans Planting Timeline — Tarrant County, TX

Scarlet Runner Beans Planting Calendar

Activity When Date Range
Start Indoors January 28 Jan 28 – Feb 11
Transplant Outdoors April 1 Apr 1 – Apr 15
Direct Sow March 25 Mar 25 – Apr 15
Harvest June 3 Jun 3 – Jul 8

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March Direct Sow
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 · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

239 days in Tarrant County

Growing Tips for Scarlet Runner Beans in Tarrant County

Direct sow Scarlet Runner Beans outdoors after March 18 in Tarrant County when soil has warmed and frost danger has passed.

With Tarrant County's clay soil (45% 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 Tarrant County, TX?

Tarrant County is in Zone 8b with an average last frost of March 18. Plan your Scarlet Runner Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Tarrant County, TX?

Tarrant County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 18 and first fall frost is November 12.

🌱

Your Tarrant County Garden Planner — Free

A 24-page printable planner built for Tarrant County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Tarrant County, TX. 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.