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When to Plant Scarlet Runner Beans in USDA Zone 4b

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 4b, the average last spring frost is around May 1 and the first fall frost is around October 3, giving you a growing season of approximately 155 days.

Zone 4b Moderate season
155 days
Last Spring Frost May 1
155 growing days
First Fall Frost October 3

Scarlet Runner Beans Planting Timeline — Zone 4b

Where Is USDA Zone 4b?

The map below highlights the states that contain Zone 4b. 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 4b

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors May 22 May 22 – Jun 5
Direct Sow May 15 May 15 – Jun 5
Harvest July 24 Jul 24 – Aug 28

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

Month-by-Month Timeline

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

Free Zone 4b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 4b 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

-25°F to -20°F average annual minimum

Growing Season

155 days (Zone 4b average)

Planting Specifications

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

Growing Tips for Zone 4b

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

Level Up Your Garden

Saving Scarlet Runner Beans Seeds

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Protect plants from frost, wind, and pests while letting light and water through.

Related Plants

Frequently Asked Questions

When should I plant Scarlet Runner Beans in Zone 4b?

In Zone 4b, plan your Scarlet Runner Beans planting around the average last frost date of May 1. Start seeds indoors around February 27. Direct sow outdoors around May 15. Transplant seedlings around May 22.

Can Scarlet Runner Beans grow in Zone 4b?

Yes, Scarlet Runner Beans can grow well in Zone 4b, hardy in USDA zones 3a through 11b. Zone 4b has a growing season of approximately 155 days, which is sufficient for Scarlet Runner Beans (60-80 days to maturity).

When can I harvest Scarlet Runner Beans in Zone 4b?

In Zone 4b, expect to harvest Scarlet Runner Beans from July 24 – August 28. Scarlet Runner Beans takes 60-80 days from planting to harvest.

What is the last frost date for Zone 4b?

The average last spring frost in Zone 4b is around May 1, and the first fall frost is around October 3. This gives a growing season of approximately 155 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.

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Plan Your Garden with Confidence

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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: April 2026.