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When to Plant Scarlet Runner Beans in USDA Zone 4a

Zone 4a Zone 4a June

Top priorities for Zone 4a gardeners in June

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Zone 4a.

Avg. last frost May 13
Avg. first frost September 28
  1. Plant out scarlet runner beans

    Your last frost (May 13) has passed. These warm-season crops can handle outdoor soil now.

Looking ahead to July
  • Starting indoors: scarlet runner beans
Download your personalised Zone 4a planting plan →

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 4a, the average last spring frost is around May 6 and the first fall frost is around September 28, giving you a growing season of approximately 145 days.

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Zone 4a Short season
145 days
Last Spring Frost May 6
145 growing days
First Fall Frost September 28

Scarlet Runner Beans Planting Timeline — Zone 4a

Where Is USDA Zone 4a?

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

Activity When Date Range
Start Indoors March 4 Mar 4 – Mar 18
Transplant Outdoors May 27 May 27 – Jun 10
Direct Sow May 20 May 20 – Jun 10
Harvest July 29 Jul 29 – Sep 2

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 Harvest
August Harvest
September Harvest
October
November
December

Free Zone 4a Planting Calendar PDF

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

-30°F to -25°F average annual minimum

Growing Season

145 days (Zone 4a average)

Planting Specifications

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

Succession Planting Scarlet Runner Beans in Zone 4a

2
successive plantings in Zone 4a's ~145-day season

Sow every 6.9 weeks for continuous harvest throughout the season.

Growing Tips for Scarlet Runner Beans in Zone 4a

Zone 4a has a short growing season (~145 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

💡
LED Grow Lights $25-60

Full-spectrum LED lights for starting seeds indoors when daylight is limited.

🔥
Seedling Heat Mat $15-35

Warm soil for faster germination of heat-loving crops like tomatoes and peppers.

🪡
Floating Row Covers $12-30

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 4a?

In Zone 4a, plan your Scarlet Runner Beans planting around the average last frost date of May 6. Start seeds indoors around March 4. Direct sow outdoors around May 20. Transplant seedlings around May 27.

Can Scarlet Runner Beans grow in Zone 4a?

Yes, Scarlet Runner Beans can grow well in Zone 4a, hardy in USDA zones 3a through 11b. Zone 4a has a growing season of approximately 145 days, which is sufficient for Scarlet Runner Beans (60-80 days to maturity).

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

In Zone 4a, expect to harvest Scarlet Runner Beans from July 29 – September 2. Scarlet Runner Beans takes 60-80 days from planting to harvest.

What is the last frost date for Zone 4a?

The average last spring frost in Zone 4a is around May 6, and the first fall frost is around September 28. This gives a growing season of approximately 145 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 Zone 4a Garden Planner — Free

A 22-page printable planner tailored to Zone 4a. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

Instant PDF download. No spam, unsubscribe any time.

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: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.