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When to Plant Scarlet Runner Beans in USDA Zone 3b

Zone 3b Zone 3b May

Your May planting checklist for Zone 3b

A quick May briefing for Zone 3b gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 16
Avg. first frost September 22
  1. Direct-sow scarlet runner beans

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

June prep starts now
  • Transplants going out: scarlet runner beans
Send me my free Zone 3b Planting Guide →

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.

In Zone 3b, the average last spring frost is around May 10 and the first fall frost is around September 22, giving you a growing season of approximately 135 days.

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Zone 3b Short season
135 days
Last Spring Frost May 10
135 growing days
First Fall Frost September 22

Scarlet Runner Beans Planting Timeline — Zone 3b

Where Is USDA Zone 3b?

The map below highlights the states that contain Zone 3b. Click any state to see the Scarlet Runner Beans planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Scarlet Runner Beans Planting Calendar — Zone 3b

Activity When Date Range
Start Indoors March 8 Mar 8 – Mar 22
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 24 May 24 – Jun 14
Harvest August 2 Aug 2 – Sep 6

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

Month-by-Month Timeline

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

Free Zone 3b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 3b with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

Days to Maturity

60–80 days

Soil pH

6 – 7

Zone Temperature Range

°F to °F average annual minimum

Growing Season

135 days (Zone average)

Planting Specifications

Planting Depth1 inches
Plant Spacing15 inches apart
Row Spacing24 inches between rows

Succession Planting Scarlet Runner Beans in Zone

2
successive plantings in Zone 's ~135-day season

Sow every 6.9 weeks for continuous harvest throughout the season.

Growing Tips for Scarlet Runner Beans in Zone

Zone has a short growing season (~135 days). Start Scarlet Runner Beans indoors early and use season-extension techniques like row covers and cold frames.

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
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Saving Scarlet Runner Beans Seeds

Recommended for Your Garden

🌱
Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

🧪
Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

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Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

Related Plants

Frequently Asked Questions

When should I plant Scarlet Runner Beans in Zone 3b?

In Zone 3b, plan your Scarlet Runner Beans planting around the average last frost date of May 10. Start seeds indoors around March 8. Direct sow outdoors around May 24. Transplant seedlings around May 31.

Can Scarlet Runner Beans grow in Zone 3b?

Yes, Scarlet Runner Beans can grow well in Zone 3b, hardy in USDA zones 3a through 11b. Zone 3b has a growing season of approximately 135 days, which is sufficient for Scarlet Runner Beans (60-80 days to maturity).

When can I harvest Scarlet Runner Beans in Zone 3b?

In Zone 3b, expect to harvest Scarlet Runner Beans from August 2 – September 6. Scarlet Runner Beans takes 60-80 days from planting to harvest.

What is the last frost date for Zone 3b?

The average last spring frost in Zone 3b is around May 10, and the first fall frost is around September 22. This gives a growing season of approximately 135 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Scarlet Runner Beans?

Good companion plants for Scarlet Runner Beans include Corn, Squash Summer. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Your Free Printable Garden Planner

A 24-page printable planner tailored to your zone. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — 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.